Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
METHOD AND STRUCTURE FOR
STAINING OF BI_LOCIC SLIDES
Background of the Invention
Field of the Invention
The invention generally relates to microscopic
exarnination of biologic specimens mounted on glass slides,
and specifically involves the staining of such biologic
specimens in preparation for microscopic examination. The
staining and examining of biologic specimens occurs daily
in great numbers in hospital laboratories, emergency rooms,
clinics, biology departments, blood banks, and many physi-
cians' offices, ve-terinarian offices and hospitals. The
slides used are of glass and generally have a 1" x 3" face
dimension, and a lmm thickness. Some slides have a slightly
different face dimension of 25mm x 75mm or a different thick-
ness of l.2mm. The specimens to be stained and examined
may, for instance, be tissue, blood sputum, or urine. The
biologic specirnents are usually smeared on the glass slide
and leEt to air dry, often with heat or reagent fixation.
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The Prior Art
To stain a biologic specimen fixed on a glass
slide, it is necessary to bring a staining liquid or reagen-t
into contact with the specimen on the slide. For the
presen~ purposes it will be understood that the term stain-
ing includes application -to the specimen of any of various
liquids or reagents during a staining process, even if a par-
ticular liquid does not itselE produce the actual staining.
In one widely used prior art method of staining,
the slide is placed horizontally, specimen up, on a rack sus-
pended in a sink. The staining liquid is poured or dripped
from a bottle over the slide to flood the specimen. This
technique wastes expensive staining liquid, since much more
liquid is generally squeezed or dripped than is actually
needed for stainingO Also, the sink becomes stained and un-
sightly after a period oE time from the overflow liquid.
The operator's fingers become stained when the specimen is
picked up. When the bot-tle reagents remain in the sink area
for a prolonged period of time, the fluid can deteriorate or
become contaminated, intentionally or accidentallyO
It generally re~uires from 6 cc to 8 cc of each
reagent to perform a specific examination with the above
technique.
A less common alternative prior art method is to
place the slide or slides vertically in a rack, and then to
dip the rack with the slide into a container of staining
liquid. This too uses an amount of dye far in excess of
that actually necessary for staining, and, where the reagent
is used for more than one slide, contamination often occurs.
Likewise, this technique involves pouring liquid from
bottles into containers and pouring the staining liquid from
containers into sinks.
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3 A third, again less common procedure is to use
4 an automated staining device. Large hospitals with heavy
workloads are more inclined to use this method. The
6 machinery involved in such automated method is extremely
7 expensive and can only be justified where the amount of
B staining is extremely heavy. The cost of such machines
9 prohibits their use in most staining operations. Further-
more, automated staining devices are only available for
11 one or two stains.
12
13 Summary of the Present_Invention
14 In our co-pending Canadian application serial
number 426,724, April 26, 1983 for METHOD AND STRUCTURE
16 FOR ST~INING OF BIOLOGIC SLIDES, a slide with a specimen
17 fixed thereon is inserted vertically, lengthwise, into a
18 confined chamber formed within a container. The slide is
19 preferably guided and positioned within the chamber on
tracksO A thin film of staining liquid is formed on each
21 face of the slide when the slide displaces a pool at the
22 bottom of the chamber into confined spaces adjacent to
23 the faces of the slide. The volume of staining liquid
24 used is approximately equivalent to the amou~t of liquid
necessary to form the thin film on each face of the
26 slide. This amount can be as little as 1 cc.
27
28 ~hen sealed, the container is rendered tamper-
29 proof so that the contents cannot be adulterated prior to
use, thus preventing a false reading of the stained
31 slide.
32
33 When the stained slide is vertically withdrawn
34 from the chamber, the staining liquid drains off the
slide and retuxns to a pool at the bottom of the chamber.
36 The container and used liquid can then be disposed of.
37 The slide may be inserted and withdrawn from the chamber,
38 and subse~uently handled, by a portion of the slide which
39 continuously extends above the chamber.
~ ~t
7~
Substantially less stainin~ liquid is required
than in the prior art; a fresh batch of reagent is provided
for each specimen; sinks are not stained since the liquid
remains within the chamber; the operators' fingers do not
become stained, since the staining liquid remains within
the chamber; and, since the stain is prepackaged, the method
is quicker and more time eficient.
The container is a disposable one intended for
one use, and has a cover or stopper which seals the chamber
and liquid until there is such use. The container is render-
ed tamperproof giving assurance that the staining process
will yield a true result. After the staining is complete,
the chamber may be easily resealed before disposal to avoid
any subsequent spattering or leakage of stain f om the cham-
ber.
The above embodiment relates to a single slide,while the embodiment now to be described relates to simul-
taneously staining a m~lltiplicity of slides.
The inventive concept of utilizing a thin film
of staining liquid on each face of the slide, wherein the
film is formed from a limited pool of staining liquid which
is displaced by the immersion of the slide itself into the
container, remains the same as in the prior application
referred to above, but the present embodiment permits the
basic concept to be used with a multiplicity of slides.
The present invention uses a holder that posi-
tions, spaces and secures slides with respect to one another.
The spacing and positioning of the slides in the holder
is critical to achieving the effect sought in the invention,
namely a thin film on the face of each slide which is formed
by the slides themselves in cooperation with the container
when the slides are immersed into a limited pool which occu-
pies only a portion of the container when the slides are
not immersed therein. The slides, while spaced, positioned
and secured in the holder, are inserted into a special,
(`7~
matching, container holding a limited pool of staining liquid.
~he slides displace li~uid of the pool, in the fashion set
forth in the parent application, so that a thin fil~ is
formed on the faces of the slides.
When the slides, by means of the holder, are with-
drawn from the containe~, the ilms of staining fluid fall
back into the container and reform substantially the same
pool as originally formed.
The slides are then removed from th~ holder for
further processing.
The holder, container, and pool are specifically
designed for a designated number of slides, and it is intended
that, in the preferred use of the system, no more and no less
than the designated number of slides be used in and with
that particular container, holder, and pool.
As with the single slide embodiment disclosed
in the prior application, preferably the container is ini-
tially sealed with the staining fluid therein, and is re-
sealed after use and before discard. The holder is, de-
sirably, removably attached to the container prior to use,so that the elements of the invention are presented together
for use in combination.
Of course, a cooperating container, holder, and
staining liquid pool can be prod~ced for any plurality of
slides within reason, but it is contemplated that the most
popular use w~ll be a five-slide embodiment.
Brief Description of the Drawin~s
Fig. 1 is a perspective view of a slide staining
device.
Fig. 2 is a pers~ective view of a conventional
glass slide of either metric or ~nglish dimensions.
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Fig. 3 is a ~erspective view similar to Fig. 1
showing the slide staining device with the cover removed
and a slide inserted.
Fig. 4 i~ a view of a conventional slide such
as shown in Fig. 2, haYing been stained in the device of
Fig. 1.
Fiqs. 5 through 8 are sectional elevational views
showing a slide in successive stages of its insertion into
the device of Fig. 1 of the invention.
Fig. 9 is a graph illustrating a principle involved
in the steps of Figs. 5 through 8.
Fig. 10 is an enlarged sectional elevational view
taken on the line 10 10 of Fig. 1~ showing in greater detail
the interior design of the staining device of Fig. 1.
Fig. 11 is a ~ransverse sectional view taken on
the line 11-11 of Fig. 10, showing still further details
of construction.
Fig. 12 is a plan view of the staining device
directly beneath the foil cover taken on the line 12-12
of Fig. 10~ showing details of the slide entrance aperture
on the upper face of the staining device.
Fig. 13 is a sectional plan view taken on the
line 13-13 of Fig. 10, showing the profiie and proportions
of the i~terior chamber and slide~guiding slots of the stain-
ing device.
Fig. 14 is an enlarged sectional elevational viewsimilar to Fig. 10, but showing a slide fully inserted in
the staining device, such as is shown in Fig. 3, and showing
the combined propo~tions and the positions of the slide
and slide-staining device in use.
~l~',{`~ ( ~7~
Fiy. 15 is a transverse sectional elevational
view taken on the line 15-15 of Eig. 14 showing central
positioning of a slide carried in slots and showing liquid
displacement chambers formed Oll the front and rear faces
of the slide.
Fig. 16 is a sectional plan view taken on the
line 16-16 of Fig. 14, showing relative proportions and
positions of the slide and slide-staining device, and liquid
displacement chambers formed on the front and rear sides
of the slide.
Fig. 17 is a perspective view of the multiple
slide staining tank of this invention, with the seal cover
partially removed.
Fig. 18 is an exploded perspective view showing
both the slide holder and staining tank of the invention.
Fig. 19 is a perspective view of both the slide
holder and staining tank in a co-acting condition in accord-
ance with this invention.
Fig. 20 is a perspective view of the empty slide
holder of this invention prior to loading.
Fig. 21 is an exploded perspective view of the
slide holder shown in Fig. 2Q showing all the co-acting
elements of the slide holder of this invention.
Fig. 22 is a perspective view of the slide holder
of Figs. 20 and 21 being loaded with five slides to be stained.
Fig. 23 is a sectional elevational view taken
on the line 23-23 of Fig. 22, showing the five slides loaded
in the holder, prior to clamping thereirl.
Fig~ 24 is A sectional plan view taken on the
line 24-24 of Fig. 23 showing additional details of the
five loaded slides loosely held by the slide holder.
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Fig. 25 is a sectional elevational view similar
to Fig. 23 but showing the five slides clamped in tightly
held spaced relation~hips, and with the five slides extend-
ing in planes normal to the top and bottom faces of the
slide holder.
Fig. 26 is a view simil~r to Fig. 24, ~ut showin~
the slides in a clamped position.
Fig. 27 is a side sectional elevational view of
the slide staining tank taken on the line 27~27 of Fig.
17, showing interior details of the tank.
Fig. 28 is a front sectional elevational view
of the slide staining tank taken on the line 28-28 of Fig.
17, showing additional details of the tank interior.
Fig. 29 is a side sectional elevational view taken
on the line 2~-29 of Fig. 19, showing details of the tank
interior when in engagement with the loaded slide holder.
FigO 30 is a front sectional elevational view
taken on the line 30-30 of Fig. 29, showing additional details
of the tank interior when engaged with the loaded slide
holder and showing the resultant upward displacement of
a staining fluid about the slides.
Des~ri~tion of the Preferred Embodiments
A conventional slide 20 is shown particularly
in Figs. 2 and 4. The slide 20 is simply a rectangular
piece of glass 21 on which a specimen 22 is mounted ~or
microscopic examination. The slide has opposed flat sur-
aces or faces 23 and 25, opposed long edges 26 and 27,
and opposed short edges 28.
The most commonly used slide has a length (Ls)
of approximately 3", a width (Ws) of approximately 1", and
a thickness (Ts) of approximately lmm. In some instances,
the slide may have a LS of 75mm and Ws of 25mm, or a TS
of 1.2mm.
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. 9
qlhese dimensions may vary slightly with different
manufacturers. For instance, thicknesses may vary from
.0525" to .0325~, and the width may vary from l.Q16" t~
.964".
The specimen 22 is prepared and then affixed to
a face of the slide in any well known manner such as by
use of air drying, heat, or reagent ~ixation. The specimen
22 is generally positioned at the center of one of the slide
faces, with a clear zone, free of the specimen, on each
end of the face. The specimen is virtually invisible at
this point, prior to staining.
The slide 20, with the unstained specimen 22 thereon,
is intended to be inserted into a disposable slide-staining
device 30~ Device 30 is desirably formed of a transparent
or translucent plastic into a generally long rectangular
configuration having proportions yenerally conforming to
the proportion of ~he slide 20. The device is intended to
be used vertically, and has a top 31, a bottom 32, edges
33 and sides 35 and 36 A collar or flange 29 surrounds
top 30 and has a flat surface thereon.
An internal cavity or chamber 40, likewise is
rectangular in configuration and again, conforms generally
to the proportions of the slide 20. The internal cavity
40 has opposed tapered vertical tracks 41 and 42, along
the vertical edges 43 and 45 of the cavity extending from
the top 40 of the cavity to the bottom 47. The cavity also
has opposed sides 48 and 50.
The cavity 40 has at its upper end a sloping~
downwardly converging portion 51 having beveled edges 52
and sides 53.
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A cover or seal 55 is a~fixed to the top 31 on
collar or flange 29 by suitable means, such as heat sealing
or adhesive. The cover is intended to be peeled back by
grasping and pulling on tab 56 prior to use, so that the
cavity 40 is exposed
A pool of staining liquid 60 is contained within
the caYity and extends about halfwa~ up the cavity, as seen
in Figs. 1 and 10.
The device is intended to be manufactured at a
central facility whereat it is sealed with the staining
liquid therein, as seen in ~ig. 1.
As seen in Figs. 5 through 8, there is shown in
sequence views of a slide 20 being inserted into the cavity
40. In FigO 5, the slide 40 with a biological specimen
22 to be s~ained af~ixed thereon, is shown entering the
cavity 40 on tracks 41 and 42. The slide 20 i5 spaced from
the opposing sides 48 and 49 as seen best in Figs. lS and
16. The slide in Fig. 5 is just about to contact the upper
surface of the pool 60, which is the static liquid level.
20 The static liquid level is at a heighth of Hl above the
bottom of the cavity.
In Figs. 6 and 7, the slide progressively descends
into the cavity below the pool, the liquid in the pool is
displaced and rises until the dynamic fluid level reaches
H2 as seen in Fig. 8, when the slide is fully inserted.
At this point, the staining liquid entirely covers specimen
22. Hl is approximately one~half of ~2. H2 also represents
the heighth of the cavity as seen best in Fig. 14.
In Fig. 9~ the principle described and shown in
Figs. 5 through 8 is illustrated in yraph form. As the
slide is submerged below the static liquid level, there
is a corresponding rise in the dynamic liquld level of the
staining liquid in virtually a straight line relationship.
C~7~
As the slide is removed from the staining li~uid,
after being left therein for an adequate period to accomplish
staining, the slide is withdrawn and the reve~se s~quence
occurs. The liquid level alls correspondingly as the liquid
drains from the side of the slide into the pool. There
is some residual staining liquid that adheres to the speci-
men and the slide, and of c~urse the pool heighth at the
end of staining drops correspondingly below the static liquid
level, when the slide is withdrawn from the device. The
slide when withdrawn from the device 30 has thereon the
stained specimen 54 as seen in Fig. 4. Since the device
is intended for a one-time use, such drop in the po~l heighth
and volume is not objectionable.
The tapPred or guide portion 51 with beveled edges
lS 52 and beveled side 53 permits easy insertion of the slide
into the tracks. It also acts as a well to catch any over-
flow of the staining liquid, including any splashing where
the slide is dropped rapidly into the cavity. A collar
or guide portion 29 extends around the upper end or top
f the device and is integral therewith. Flange 29 has
desirably a flat top portion 63 which permits a foil or
cover 55 to be suitably secured thereto as by adhesive,
or by a s~itable heat-sealing technique. The foil can be
of a metallic or a plastic material capable of being peeled
back from the covering by grasping a tab portion 56 and
pulling to a completely open position, as seen in Fig. 3.
The cap portion in sealing and covering position is shown
in FigsO 10 and 11.
There is variability in the width and thickness
f slidesl even those claiming to have specific dimensions.
By tapering the tracks, the device will receive a slide
of variable thickness and variable width and still keep
the slide away from the inside wall of the cavity. Addi-
tionally, the tapered tracks assure that only the edge of
the slide will touch the track and not the surface which
contains the specimen.
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The slide 20 when inserted into the cavity 40
on ~he tracks 41 and 42 assumes a very definite position
and posture within the cavity and witi- resp~ct to the sides
or walls 48 and 49 of the cavity 40.
As seen in Fi~s. 14 to 16 inclusive, the slide
20 when inserted into its ~ottommost position has a top
portion 61 which extends above the cavity 40 and top 31
of the device 30. The top portion ~1 of the slide 2D is
clear of any specimen 22, since the specimen zone is conven-
tionally in the middle of the slide as shown in Fig. 14
hy phantom lines. The portion 61 of the slide 20 remaining
above the device 30 is used to grasp the slide for inserting
into the device and for withdrawing the slide from the device.
The slide is also grasped by this portion during the rinsing
subsequent to the staining. In this way, the operator's
fingers remain free of contact with the staining solution,
and free of the dye. Approximately one-sixth of the length
of ~he slide LS extends above the device 30.
The spec;men 22 is stained when the slide is fully
inserted as shown particularly in Figs. 14 through 16 inclu-
sive. The slide as seen particularly in Figs. 15 and 16
i5 positioned centrally of the cavity 40 and spaced from
walls or sides 48 and 49. The slide 20 has adjacent to
each face thereof spaces 65 and 66 which contain staining
liquid. The slide can be inserted with the specimen 22
facing in either direction as the slide 20 enters the cavity.
The face of the slide 20 and the specimen 22 thereon is
positioned so that the specimen 22 cannot contact the sides
o~ the cavity, but rather the specimen is held in a way
that exposes it to the staining liquid in the space 65 or
66 formed ~y the slide and the side of the cavity. A minimum
amount of stainin~ llquid is necessary to stain the specimen
when the slide is so positioned. This is clearly shown
in the sectional views in Figs. 15 and 16.
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~13-
It will be seen from the above description that
the space 65 anc7 66 adjacent to each face of the slide when
the slide is fully inserted into the cavity is a flat thin
space which contains a suitable amount of staining liq~id
to properly stain the specimen thereon, without excess use
of such liquid. ~rthermore, the slide itself is used to
position this liq~id adjacent to the faces of the slide,
and the specimen on one of the faces. It will be seen that
it does not matter as to which direction the specimen ~aces
when inserted into the cavity, since there is film on both
faces of the slide.
The slide itself, in cooperation with the container,
creates the film adjacent to the slide faces for staining,
and then permits the liquid in those spaces to drain back
lS into the bottom o~ the cavity and pool formed therein when
the slide is removed.
In Figs. 10 throu~h 16 inclusive, there is shown
in detail the interior of the device of Fig. 1. Ws is the
width of the slide ~l LS is its length, and TS is its thick-
ness~ ~2~ which is the heighth oE ~he cavity, as well asthe heighth of the dynamic liguid level discussed above,
is approximately three~quarters of the slide len~th Ls~
The teacks 41 and 43 comprise tapered walls in
the edges of the cavity, as shown. The width between the
2~ tracks, WT, as seen in Fig. 13! is sli~htly greater, for
instance, .02~ greater, than the width of the slide Ws,
so that there is adequate clearance for the slide to move
in the tracks. TT, the thickness of the track at its tapered
end, is slightly less, for instance, .016'i less, than the
30 thickness of the slide Ts~ Y, the thickness oF the cavity,
is approximately twice the slide thickness, Ts. By virtue
of the tapered tracks 41 and 42, the slide, when inserted
în the tracks, is centr~lly spaced between the side walls
,~f;~ 7~
of the cavity, 48 and 49. Where the thickness of the cavity
is twice that of the sli.de, the thickness of the spaces
formed on each face of the slide when the slide is inserted
will be approximately one-half the thickness o the slide.
By virtue of the tapered tracks 41 and 42, slides
with slightly varying dimensions ~s set forth above will
be suitably spaced within cavity 40. The tapered walls
of the tracks 41 and 42 will compe~sate for these slight
variations by guiding the slide at its edges thereof while
still positioning the slide. Even with a slide having the
smallest width andJor thickness within the variable dimen-
sions, the slide is still spaced from the sides of the cavity,
although all edges of the slide may not be in firm contact
with the tracks. Even though such a relatively small slide
~ay have more freedom to move about within the cavity than
a relatively large slide, the restraint imposed on the corners
of the slide by the tapered walls of the tracks keeps the
slide spaced from the cavity walls so that-a film of staining
fluid can be formed adjacent the slide faces.
It should be understood that the dimensions given
above are merely illustrative to indicate a suitable dimen-
sioned container to practice the invention~
~eferring now to the preferred embodiment of the
invention ~or simultaneously staining a multiplicity of
slides, and with partic~lar reference to Figs. 17-30, slides
120 are of t.he nature, size and design described above with
respect to slide 20.
The containe 130 may be genexally similar to
the container 30 described above, in shape, heighth, and
30 width, except the horizontal depth of the container is ex- ~ :
tended to receive a plurality of slides, rather than onl~
one, as will be described. The container 130 has an open
top 131, a bottom 132, edges 133, 134, sides 135, and 136,
and collar or flange 129.
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The internal cavity or main chamber 140 of con-
tainer 130, has fo~r tracks s~ch as 141 and 142 in its four
vertical corners, vertical edges 143 and 145, a bottom 1~7,
and opposed sides 14B and 150.
In the version shown, the main chamber has at
its top an overflow chamber 160 formed in the flange portion
129 which has side walls 168,170 formed by sides of the
mai~ chamber 140, end walls 172,174 and bottom ledges such
as 180.
~0 A seal cover 186, similar to seal 55 described
above, is affixed to top 131 of the container.
The slides are spaced, positioned, and securely
held in holder 200, which consists essentially of a drawer
202, a case 204, and spacers such as 206. The spacers are
slidably and pivotally suspended in case 204 on pivot trun-
nion pins such as 210 which ride in tracks 212 and 214 on
the interiors of the opposed sidewalls 215,216 of the case.
Drawer 2~2 slides into case 204 so that when moved inwardly
it pushes aqainst at least the foremost spacer 217~
The case 204 has a closed top wall 2~8 and an
open bottom. (The case is shown inver~ed, in the loading
position, in Figs. 20, 21, 22, 23 and 25. ) The side walls
215~216 contain respective slots 224 and 226, an open front
and a closed back wall 230.
The tracks 212 and 214 in the case 204 are each
formed by parallel ridges which deine channels 232, 234
for receiving the pins 210 on the spacers.
The spacers are thin, flat rectangles which pre-
ferably have, at their long edges nearest the pins, a tapered
edge or point for facilitating insertion between them of
one end of the slides~ The pins are near the edges o~ the
spacers so the spacers hang free and loose in the trAcks
before loading of the slides. Preferably, these spacers
are all alike.
',C)(~7~
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The drawer 202 has a front wall 300, push and
pull knobs or ears 302, 304 at the opposite sides of the
front wall, sides 306,308, and diagonal interior braces
310, 312 extending b~tween the front wall and the side walls
5 of the drawer~ Th~ side walls 306,308 each have a cam tooth
such as 314 in~ended to ride in a corresponding slot such
as 226 in the side wall of the case when the drawer is in-
serted into the case. The drawer side walls fit inside
of, and in sliding engagement with, the case side walls.
Each of the cam teeth 314 has a sloping surface such as
320 which permits the drawer to be inserted into the case
until the teeth engage in their corresponding slots 224 and
226, after which the flat end surface 322 on the tooth prevents
the drawer from uninter.tionally being pulled all the way
15 out of the case.
The drawer is desirably made of a relatively flexi-
ble plastic materi~l such as ~olyethylene, wherein there
is a degree of give~ par~icularly to the sides beyond the
braces, for putposes which will be explained later. The
20 spacers are likewise desirably made of such flexible material.
In contrast to the drawer and space~s, the case
is made of a relatively rigid material such as glass-filled nylon,
so that the relatively flexible drawer and spacers, in com-
bination with the relatively rigid case, will permit the
25 drawer to lock the spacer~ to the case as described herein-
after.
It is intended that container 130 contain a con-
fined or limited pool of s~aining fluid 360. As best seen
in Figures 27 and 2~, this pool extends to a height H~ which
3~ is preferably somewhat over one-half of the height of the
chamber 140.
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As with the single slide embodiment shown in Figs.
1 through 16, it is intended that slides 120 be inserted
downwardly into this pool 360, whereby staining liquid o
the pool will be displaced upwardly in the main chamber
5 substantially to the top thereof without overflowing into
the overflow chamber, but in the event of excess upward
flow of displaced liquid this may be caught in the over~
flow chamber 160. In a preferred design, the proportion
of parts and depth of pool are such that no substantial
10 overflow occurs, and in such case the large overflow cha~ber
can be eliminated and the top of the container made as in
the single-slide version of Figs. 1-46.
The slides are held in exact spaced relationship
with each other and the container so that a thin film is
15 formed on both sides of the slides. The space between the
slides conforms to the thickness of the spacers. Desirably,
this thickness is approximately equal to the thickness of
the slides themselves, which as indicated above can be about
1 mm. The spacing is such that when the spaced slides are
20 secured in the holder, and the slides are immersed in the
limited pool in the container substantially to ~he bottoM
thereof, the pool will be displaced so that the staining
liquid rises in thin films which reach and cover substan-
tially all the slide portion which extends into main chamber
25 of the container, and particularly the portions to which
the specimens are affix~d.
The positioning and spacing of the slides are
accomplished in the holder, which initially is placed on
its top, in an inverted position. The spacers are allowed
30 to hang freely on their trunnion pins in tracks 212,214 as
seen in Figs. 22, 23 and 240 At this tîme, the drawer 202
;
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is open, and side walls 306 and 308 of the drawer are para-
llel ~n~ in a rela~ed ~osition, whereb~ the dra~er can slide
Freely in the c~se, except that the drawee cannot be with-
drawn compLetely out beca~se of the interfering action oE
cam teeth 314
As shown in Fig. 22, slides 120 are then inserted
between the spacers such as 206, with the beveled edges
of the spacers aiding entry of the slides between the spacers.
The spacers and slides are preferably of the same width.
The width of the case between its side walls is equal to
the width of the slides plus a slight clearance dimension.
During assembly, the slides are dropped to the "bottom"
of the inverted case, so that the straight edges of the
ends of the slides rest on the interior of the top wall
of the case. When the necessary n~mber of slides has been
inserted in the holder, which is five for the five-slide
holder and container embodiment shown, the drawer is pushed
closed from the position shown in Figs. 23 and 24 to the
position shown in Figs. ~5 and 26.
Sidewalls 306 and 308 of drawer 202 terminate
at their free ends in respective wedges 370, 372 having
respective, confronting, tapered wedging surfaces 374,376
adapted to enter the above-mentioned clearances between
~pacers and side walls when the drawe~ is closed. Also,
when tl,e drawer is closed, the outer ends of sidewalls 306
and 308 are spread outward due to the wedging actions of
surfaces 374, 376 against the ends of the spacers. The
wedges are formed in the side walls beyond the braces 310,
312, so that the side walls are held relatively parallel
up to the end of the braces, while the remaining outer end
portions of the side walls are relatively free to flex out-
ward under the influence of the spacers, and against the
inside of the side wal]s of the case. The resistance of
the spacers and slides against the wedges therefore serves
to jam the wedges against the side walls of the drawer,
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-19-
so that the drawer, the slides and the spacers are locked
in position, with the slides clamped between the spacers.
The spacers, Which are relatively flexible, give slightly
against ~he har~ glass of the slides and then serve to
cushion-grip the slides. ~he slides are now held parallel
to one another, and evenly spaced from each other by pre-
determined distances.
If there is any slight misalignment of the slides
because the ends of the slides are not touching the interior
of the case top, or because the slide ends are not entirely
square with the slide sides, any such slight misalignment
can be remedied by forcing the slides into the correct posi-
tion manually, with one's fingers.
The outside dimensions of the five-slide group
extending from the holder closely conform to the chamber
designed for the ive slide staining operations~ These
dimensions are such that when the holder is inverted from
the loading position and the exposed portions of the slides
inserted into the container, the edges of the outside slides
touch the sides of the tracks such as 141,142 in the con-
tainer, whereby, when the slides, by means of the holder,
are inserted into the container, there is formed a thin
space adjacent to each of the outside faces of the outside
slides. The tracks such as 1~1,142 can be molded integrally
with the remainder o~ the container, and may have lead-in
bevels at their entrance ends to facilitate insertion of
the slide assembly.
As the slides are immersed into the pool, the
liquid is displaced upwardly along the slide faces. The
dimension of ~he portion of the slides extending into the
holder is preferably such that when the holder comes into
contact with the top of the container, the slides almost
(i 7 ~ ~
-20-
touch, or are just slightly above, the bottom of the con-
tainer. Thus~ essentially all of the staining liquid at
this time extends in thin films across the faces of the
~lides, and across the speci~ens on the slides. The liquid
rise~ to the top of the chamber, and permis~ibly int~ the
overflow chamber if one or more of the slides is slightly
thicker than a generally standard slide.
When the specimen~ have been thus stained, the
slides are withdrawn from the container by means of the
holder. The staining fluid drains off the slides, back
into a pool of approximately the same size as the beginning
pool minus the quantity which adheres to the slide. The
container can permissibly be resealed with the original
seal, and then neatly discarded. The holder and slides
are then inverted and the slides unloaded from the holder
in essentially a reverse operation from the loading opera-
tion described above.
In order to withdraw the drawer from the case
and to release the grip of the spacers on the slides, it
is necessary to break the wedging action of the sides of
the deawer. To do this, the drawer is gripped at its ears
302 and 304 between the fingers, and an alternating rocking
motion is exerted on the drawer as the ~rawer is withdrawn
from the case, which is anchored by the fingers of the operator's
other hand. The case is desirably resting on a table during
the unloading operation. After the jamming and wedging
action of the drawer is thu~ broken, the dr~wer is withdrawn
to release the spacers and ~lides to the position shown
in Figs. 23 and 24. The slides can then be delicately re-
moved from the holder and further processed by rinsing andthe like, in the usual wayO
The holder carl optionally be washed and rinsed
and then used with a new container and pool, or the holder
can be thrown away.
It is intended that the container and holder be
mass-produced out of plastic, by, for instance, extr~sion
molding, so that the cost per unit be relatively low.
The above embodiment is illustrated with a five-
slide group. It should be understood that the same principlecan be used with respect to any desired group from, for
instance, two to ten and beyond, with each having its speci-
fically dimensioned container, holder, and pool. However,
it is contemplated that the five-slide arrangements will
be the most prevalent.
Two such five-slide holders can also be clipped
back-to-back to create a ten-slide holder. Such ten-slide
combination may then be inserted into a ten-slide container,
designed in accordance with the invention to accommodate
the ten slides.
The container shown above has an overflow compart-
ment as described~ This is generally desirable when it
is anticipated that the slides used vary somewhat in their
thickness. Since a thicker slide displaces more liquid,
the over~low chamber serves to receive and hold this over-
flow during the staining operation. Where the slides are
relatively uniform in thickness, there is no need for an
overflow chamber, since the displacement is more controlled.
In this condition, the overflow chamber can be reduced in
sizep or eliminated, as seen in the embodiment shown in
Figs~ 1 to 16.
As an aid in design, the following relations are
noted. The distance H2 by which the level of the top of
the pool of staining liquid is raised by immersion of the
slides is equal to the volume of the liquid displaced upward-
ly by the glass of the slides, divided by the average cross-
sectional area of the glass-free chamber space into which
the liquid is displaced. Designating the distance by which
the slides are immersed below the top of the original pool
as ~1~ the average cross-sectional area of the chamber above
D ( r~7~
the original pool surface with the slides removed as ACh,
and the average cross-sectional area of slide glass in the
liquid as Agl, then
H2 =
ch gl
In the simple case of a purely reetangular chamber, ~ive
slides of l mm thickness each spaced from each other and
from the chamber wal~s by l mm, and immersion of the slides
to the full depth H of the original pool, the formula pre-
diets a rise in liquid level H2 = H = H = 83H
In praetice, the height H2 will be redueed below ~his valueby any extra ehamber spaee at the edges of the inserted
slides, and inereased due to reduetions in ehamber space
eaused by tracks in the chamber.
While the invention has been described with par-
tieular referenee to specific embodiments i.n the interest
of eomplete definiteness, it will be understood that it
may be embodied in a variety of ~orms diverse from those
speeifieally shown and described, without departing from
the spirit and seope of the invention as defined by the
appended elaims.
