CA1182728A - Method and structure for staining of biologic slides - Google Patents

Abstract

Abstract of the Disclosure A disposable device for staining a biologic specimen affixed to a face or a microscopic slide wherein the slide is inserted vertically along tracks into a pool of staining liquid at the bottom of a cavity. The liquid is displaced into a flat space adjacent to each face of the slide to form a film that stains the specimen.

Description

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~THOD AND STRUCTURE FOR
~AlN~ O- "-OLOClC 'L:D`S

Back round of the Invention ~ield of the Invention Theinvention t3enerally relates to microscopic examination o~ bioloqic specimens mounted on ~lass slides, and specificallv invo]ves the staining of such biologic specimens in preparation for microscopic examination. The staining and examinin~ of biolo~ic specimens occurs daily in qreat numbers in hospital laboratories, emexgency r~oms, clinics, biology departments, hlood banks, and many physi-cians' offices, veterinarian offices-and hospitals. The slides used are of glass and qenerally have a 1~ x 3" face dimen~ion, and a 1 mm thickness. Some slides have a slightly different face dimension of 25 mm x 75 mm or a different thickness of 1.2 mm. The specimens to be stained and examined may, for instance, be tissue, blood, sputum, or urine. The biolo~ic specimens are usually smeared on the qlass slide and left to air dry, oten with heat o~ xeagent fixation The Prior Art To stain a biologic specimen fixed on a glass slide, it is necessarv to bring a staining liquid or reagent into contact with the specimen on the slide.
In one widely used ~rior art method of s taining, the slide is placed horizontally, specimen up, on a rack suspended in a sink. The staining li~uid is poured or dripped from a bottle over the slide to flood the specimen.
This technique wastes expensive staining liquicl, since much more liquid i5 generally squee~ed or dripped than is actually needed for staining. Also, the sink becomes stained and unsightly after a period of time from the overflow liquid. The operator's fingers ~ecome stalned when the specimen is picked up. When the bottle reagents remain in the sink area ~or a prolonged period of time, ~he fluid can deteriorate or become contam~nated.
It generally requires from 6 cc to 8 cc of each reagent to perform a specific examination in the above technique.
~ less common alternativ~ pxior art method i8 to place the ~lide or slldes verti~ally in a rack, and then to dip the rack with the qlide into a container of stain-in~ 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 p~uring liquid rom bottles into containers and pouri~g the staining liquid rom containers into sinks.
A third, again less common procedure is to use an automated staining device. Large hospitals ~ith heavy

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- 3 -3 workloads are more inclined to use this method. The

4 machlnery involved in s~lch autom~ted method is extreme-ly expensive and can only be justified where the amount 6 of staining is extremely heavy. The cos-t of such 7 machir.es prohibits their use in most staining opera-8 tions. Furthermore, automated staining devices are 9 only available for one or two stains.
11 Summary of the Present Invention 13 A disposable staining device intended for one-14 time use for applylng a staining liquid to a specimen fixed to a specimen zone on one o~ the opposed faces of 16 glass slide, the specimen zone being centrally disposed 17 between the slide ends comprises a container having an 18 upwardl~ opening cavity ~or receiving the slide; a quan-19 tity of staining liquid partially filling the cavity;
and a removable seal closing the cavity to contain the 21 liquid prior to use of the device. The cavity has a 22 height shorter than the length of the slide to prevent 23 an end of the slide to extend above the device when the 24 slide is fully inserted in the cavity. With this arrangement, the specimen zone on the slide is disposed 26 completely within the cavity when the slide is fully 27 inserted into the cavity regardless of which end of the 28 slide ls irst inserted. The container is also pro-29 vided with means for maintaining a spaced relationship of the opposed faces of the specimen zone of the slide 31 and the cavity walls; the cavity in the container is of 32 a size suf~icient to receive only a single slide and 33 has a cross-sectional area no greater than twice the 34 cross-sectional area of the slide; the depth of the staining liquid prior to insertion of the slide is less 36 than the distance between the upper edge of the speci 37 men zone and the inserted end of the slide. When the 38 slide is inserted in the cavity the liquid is displaced - 3a -3 to a level sufficient to cover the specimen zone and 4 thereby stain the specimen fixed thereto when a slide is so positioned between the cavity walls. The present 6 invention also encompasses a method of staining speci-7 mens fixed to a specimen zone on the face oE a slide 8 which includes providing a sealed dispensing container 9 as described above; removing the seal from the con-tainer; inserting the slide into the cavity and upward-11 ly displacing the staining liquid to stain the speci-12 men; removing the stained slide from the container; and 13 discarding the sealed container and staining liquid.

In the present invention, suhstant:ially less 16 liquid is required than in the prior art; a fresh batch 17 of reagent is provided for each specimen; sinks are not 18 stained since the liquid remains within the chamber;
19 the operator's fingers do not become stained, since the staining liquid remains within the chamber; and being a 21 prepackaged method, the method is quicker and more time 22 efficient.

The container is a disposable one intended for on~
use, and has a cover or stop~er which seals the chamber and liquid until there ~ such use.

Brief DescriDtion of the Drawings S Fig. 1 is a perspective view of the slide st~ining device of the invention.
Fig. 2 is a perspective view of a conventional glass slide of either metric or English dlmensions.
Fig. 3 is a perspective view similar to Fig. 1 showing the device with the cover removed and a slide inserted.
Fi~. 4 is a view o~ a conventional slide ~lch as shown in Fig. 2, havin~ been stained in the device of ~he invention.
lS Figs. ~ throuqh 8 are sequentially sectional elevational views showing a slide being inserted into the device of the invention.
Fig. 9 is a graph illustrating a principle ~hown in Fig~. 5 through 8.
Fig. 10 is an enlarged sectional elevational vl~w ta~en on the line 10-10 of Fig. 1, showing in greater detail the interlor desiyn of the staining device of Flg. lo Fig. 11 is a transverse sectional view t~ken on tha line 11-11 of Fig. 10, showing still fur~her d~tall~ o~
~5 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 aper ure 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 profile ~nd proportions of the interior chamber and slide-guidinq slots of the staining devic~.

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Fig. 14 is an enlarged sectional elevatlonal view similar to Fig. 10, but showing a slide fully inserted in the stainirlg device, such as is shown in Fig. 3, and showing the col~in~d proportions and the positions of the slide and slide-staining device in use.
Fig. 15 is a transverse sectional elevational view taken on the line 15-15 of Fig. 14 showing central position-ing of a slide carried in 510ts and liquid displacem~nt cha~ers formed on the front and rear face of the slide.
Fig. 16 is a sectional plan view taken on the line 16-16 of Fiq. 14, showing relative proportions and positions of the slide and slide-staining device, and li~uid displace-ment chambers formed on the front and rear side o~ the slide.

Description of the Preferred Embodiment The invention uses the convention,al slide 20 as seen particularly in Figs. 2 and 4. The slide 20 is simply a rectangular piece of glass 21 on wh~ch a specimen 22 is mounted for microscopic examination. The slide has opposed flat surfaces or faces 23 and 25, opposed long edges 26 and 27, and opposed short edges 28.
The most commonly used slide has a leng-th (Ls) of appxoximately 3", a width (Ws) of approximately 1", and a thickness (Ts) of approximately 1 mm. In some instances ~
the slide may have a LS f 75 mm and Ws of 25 mm, or a TS
of 1.2 mm.
These dimensions may vary slightly wlth different manufacturers. For instance~ thic~nesse~ may va~ from .0525" to .0325", and the width may vary from 1.016'1 to .964".
'rhe specimen 22 is prepared and then affixed to a fac~ of the slide in any well known manner ^~uch as by us~ of 27~

air drying, heat, or reagent fixation. The specim~n 22 is generally positioned at the center of one of the slide ~aces, with a clear ~one, free of the specimen, on each end of th2 face. The specimen is virtually invi~ible 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 generally conforming to the proportlon of the slide 20. The device is intendsd to be used ver~ically, and has a top 31, a bottom 32, edges 33 and sides 35 and 36. ~ collar or flan~e 29 surrounds top 30 and has ~ flat surface thereon.
An internal cavity or chamber 40, likewise is rectangular in con~iguration 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 cavitv extending from the top 46 of the cavi~y to the bottom 47. The cavity also haa opposed sides 48 and 50.
The cavity 40 has at its upper end a sloping, downwardly converqing portion Sl having beveled ed~es 52 and sides 53.
~ cover or seal 55 is affixed to the top 31 on collar or flange 29 by suitable means, such as heat sealing or adhesive. The cover ls intended to be peeled back by grasping and pulling on tab 56 prior to use, so ~hat the cavity ~0 is exposed.
A pool of staining llquid 60 is contained within the cavity and extends about halfway up the cavity, as seen in Figs. 1 and 10.

The device of the invention is intended to b~
manufactured at a central facility whereat it is sealed with the st:aining liquid therein, as seen in Fi~. 1.
As seen in Figs. 5 through 8, there 18 show~ in sequeJ.~ views of a slide 20 beLng inserted into the cavity 40. In Fig. 5, the slide 40 with a biological specimen 22 to be stained affixed thereo~ shown entering the cavity 40 on tracks 41 and 42. The slide 20 is spaced from ~he opposing sides 48 and 49 as seen best in Flgs. 15 and 16.
The slide in Fig. 5 is just about to contact the upper sur face of the pool 6~, which is the static liquid lavel~ The static liquid level is at a heighth of Hl above the bottom of the cavity.
In Fi~s. 6 and 7, the slide progressively descends 15 into the cavity below the pool, the liquid in the pool i3 displaced and rises until the dynamic fluid level reaches H~ as seen in Fi~. 8, when the slide is fully in~er~ed. At thiq point, the staining liquid entirely cover~ speci~n 22.
Hl is anproximately one~half of H2. H2 also repr9sent~ the ~o hei~hth of the cavity as seen be~t in Fig. 14.
In Fig. 9, the principle dQscribed and shown in Figs. 5 through 8, is illustrated in graph ~orm. A8 the ~lide is submerged below the static liquid level, there i~
a corresponding rise in the dynamlc liquid level of the staining liquid in virtually a straight line relationship.
A~ the slide is removed from the staining liquid, aftex being left therein for an adequate period to accomplish staining, the slide is withdrawn and the revers~ sequsnce occurs. The liquid level falls correspondingly a~ the liquid 30 drains from the side of the slide into the pool. There i~

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some residual stalning liquid that adheres to the speci-men and the slide, and of course the pool hei~hth at the end of stalning drop~ corres~ondl~ly below th~ static liquid level, when the slide is ~Yithdrawn from the device.
The slide when withdrawn from the device 30 has thereon the stained specimen 54 as seen in Fig. 4. Since the devic~ is intended for a one-time use, such drop in the pool heighth and volume is not objectionable.
The tapered or yuide portion Sl with beveled edqes 52 and beveled side 53 permuts easy insertion of the slide into the tracks. It also acts as a well to catch any over-flow of the stainin~ liquid, including any splashing where khe slide is dropped rapidly into the cavity. A collar or guide portion 29 extends around the ~Ipper end or top of the device and is intearal therewith. Flange 29 has desirably a flat top portion 63 which pexmits a foil or cover 55 to be suitably secured thereto as by adhe~ive, or ~y a suitable heat-sealing technique. The foil can be of a metallic or a plastic material capable of being peeled back from the covering by ~rasping a tab portion 56 and pulling to a completely op~n position, as ~een in Fig. 3. The cap por-tion in sealing and covering po~ition is shown ln Figs. 10 and 11.
There is variabilit~ in the width and thickne9s Of 25 slide~, even ~hose cla~m~ng to have speci~ic dimensions.
By tapering the tracks, ~he device will receive a slide of variable thickness and variable width and ~t~ll keep the slide away from the inside wall of the cavlty. Additionally, the tapered tracks assure that only the edge o the slide will touch the track and not ~he surface which contai ns the specimen.

l~he slide 20 when inserted into the cavity 40 on the tracks 41 and 42 assumes a vexy definite position and posture within the cavity and with respect to the side~ or walls 48 and 49 of the cavity 40.
As seen in Figs. 14 to 16 inclusive, the slide 20 when inserted into its bottommost position has a top portion 61 which extends abo~e the cavity 40 and top 31 of the dev~
30. The top portion 61 of the slide 20 is clear of any specimen 22, since the specimen zone is conventionally in the middle of the slide as shown in Fig. 14 by 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 dev~ce. The slide is also ~rasped by this portion during the rinsing subsequent to the stainin~. 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 the ~lide LS
extends abo~e the device 30.
The specimen 22 is ~tained when the slida is ully inserted as shown particularly in Figs. 14 through 16 in-clusive. The slide as seen partlcularly in Figs. 15 and 16 i9 positioned centrally of the ~avity 40 and spaced from walls or ~ides 48 and 49. The slide 20 has adjacent to each face thereof sp~ces 65 and 66 which contain stainlng liquld. The slide can be inserte~ with the speclmen 22 fac-ing in either direction as the slide 20 enters the cavlty.
The face of ~he slide 20 and the specimen 22 thereon i~
positioned so that the specimen 22 cannot contact the sides of the cavity, but rather the specimen is held in a way that exposes it to the staining liquid in ~he space 65 or ~%~

66 formed ~y the slide and the side of the ~avity. A
munimum amount of staining liquid is neces~ary to stain the specimen wh~n the slide is so positioned. Thi8 iS
clearly shown in the s~ctional views in Figs. 15 and 16.
It will be seen from the above description that the space 65 and 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 liquid to properly stain the specimen thereon, without excess use of such li~u1d. Furthermore, the slide itself is used to position this liquid adjacent to the faces of the slide, and the specimen on one of the faces. It will be seen that it does not matte~ as to which direction the specimen faces when inserted into the cavity, since there ~s film on both faces of the slide.
The slide itself, in cooperation with the container, creates the film adjacent to the slide face~ for ~taining, and then permits the liquid in those spaca3 to drain bacX
into the bottom of the cavity and pool for~d therein when the slide is removed.
In Figs. 10 through 16 inclusive, there is ~hown in detail the interior of the device of Fig. 1. Ws is the width of the slide 20, LS is its length, and TS i~ it~ thick-ness. ~, which is the heighth o the cavity, . a3 well a~
the heighth of the dynamic liquid level discus~ed above, i8 approximately three-quarters of the slide length, LS, The tracks 41 and 42 comprise tapered walls in the edges of the cavity, as shown. The width between the tracks, WT, as seen in Fig. 13, is slightly greater, for instance, .02" ~reater, than the width of the slide Ws, so that ~here ii2~

is adequate clearance for the slide to move in the tracks~
TT, the thickness of the track at its tapered end, i5 slightly less, for instance, .016" less, than the thickness of the ~lid~, Ts~ Y, the thickne~s of the ca~ity, i3 approximately twice thQ slide thlckness, Ts. By virtue of the tapered tracks 41 and 42, the slide, when inserted in the tracks, is centrally spaced between the sidewalls of the cavity, 48 and 49. Where the thicXness of the cavity i9 twice that of the slide, the thickness of the spaces formed on each face of the slide when the slide is inserted will be approximately ona-half the thickness of the slide~
By virtue of the ~ ered tracks 41 and 42, slides with slightly varyin~ dimensions as set forth above, will be suitably spaced within cavity 40. The tap~red walls of the tracks 41 and 42 will compensate for these ~light variations by guiding the slide at its edges thereof while still positioning the slide. Even with a slide having the smallest width and/or thickness within the variable dimensions, the slide is still spaced from the sides of the cavity, although all edges ~f the ~lide may not be in flrm contact with the tracks. Even though such a relatively small slide may have more freedom to move about within the cavity ~han a relatively large~slide, the restr~int imposed on the corners of the slide by the tapered walls o~ th~
tracks keep~ the slide spaced from the cavity walls so that a f~lm of stailling fluid can be formed adjacent the slide faces.
It should be understood that the dimensions glYen above are merely illustrative to indicate a suitably dimensioned container to practice the invention.

2~3 While the invention has been described with particular xeference to ~pecific embodiments in the interest of complete definiteness, it will be understood that it may be embodied in a variety of forms diverse

5 from those specifically shown and described, without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (20)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS
FOLLOWS:

1. A disposable staining device, intended for one-time use, for applying a staining liquid to a specimen fixed to a specimen zone on one of the opposed faces of a glass slide, the specimen zone being centrally disposed between the slide ends, said device comprising:
a container having an upwardly opening cavity therein for receiving the slide;
a quantity of staining liquid partially filling said cavity; and a removable seal closing said cavity to contain said liquid prior to use of said device;
said cavity having a height shorter than the length of the slide to permit an end of the slide to extend above said device when the slide is fully inserted in the cavity;
the specimen zone being disposed completely within the cavity when the slide is fully inserted into the cavity regardless of which end of the slide is so inserted;
means for maintaining a spaced relationship of the opposed faces of the specimen zone of the slide and the cavity walls;
said cavity being of a size sufficient to receive only a single slide and having a cross-sectional area no greater than twice the cross-sectional area of the slide;
the depth of the staining liquid prior to inser-tion of the slide being less than the distance between the upper edge of the specimen zone and the inserted end of the slide;
the insertion of the slide displacing said liquid and raising the liquid level to a level sufficient to cover the specimen zone and thereby stain the specimen fixed there-to when a slide is so positioned between the cavity walls.

2. The invention as claimed in claim 1 wherein said means for maintaining a spaced relationship of the slide faces and the cavity walls comprises guide means in said cavity for engagement with the side edges of said slide.

3. The invention as claimed in claim 1 wherein the shape of the cavity in vertical section is substantially rectangular and wherein the slide when fully inserted bottoms on the cavity lower end.

4. The invention as claimed in claim 1 wherein the width of the cavity is slightly greater than the width of the slide and wherein the thickness of the cavity is less than twice the thickness of the slide.

5. The invention as claimed in claim 1 wherein the liquid substantially fills the cavity when the slide is fully inserted therein.

6. The invention as claimed in claim 1 wherein the depth of the liquid following insertion of the slide is sub-stantially twice the depth of the liquid prior to insertion of the slide.

7. The invention as claimed in claim 1 wherein the quantity of staining liquid in the cavity comprises less than 2 cc.

8. The invention as claimed in claim 1 wherein the seal is affixed by heat sealing.

9. A disposable staining device, intended for one-time use, for applying a staining liquid to a specimen affixed to a specimen zone on one of the opposed faces of a glass slide, the specimen zone being generally centrally dis-posed equidistant the slide ends, said device comprising:

a container having an upwardly opening slot-like cavity therein for receiving the slide;
a quantity of staining liquid partially filling said cavity; and a removable seal closing said cavity to contain said liquid prior to use of said device;
said cavity having a rectangular vertical sec-tional shape, the width of the cavity being slightly greater than the width of the slide and the thickness of the cavity being less than twice the thickness of the slide;
said cavity having a height shorter than the length of the slide to permit an end of the slide to extend above said device when the slide is fully inserted in the cavity;
the slide when fully inserted engaging the bottom of the cavity;
the specimen zone being disposed completely within the cavity when the slide is fully inserted into the con-tainer regardless of which end of the slide is so inserted;
the configuration of the cavity permitting engage-ment of the side edges of the slide with the cavity walls and preventing contact of the specimen zone of the opposed faces of the glass slide faces with the cavity walls;
the depth of the staining liquid prior to inser-tion of the slide being less than the distance between the upper edge of the specimen gone and the inserted end of the slide;
the insertion of the slide displacing said liquid and raising the liquid level to a level sufficient to cover the specimen zone and thereby stain the specimen fixed there-to when the slide is positioned between the cavity walls;

10. The invention as claimed in claim 9 wherein the liquid substantially fills the cavity when the slide is fully inserted therein.

11. The invention as claimed in claim 9 wherein the depth of the liquid following insertion of the slide is sub-stantially twice the depth of the liquid prior to insertion of the slide.

12. The invention as claimed in claim 9 wherein the quantity of staining liquid in the cavity comprises less than 2 cc.

13. A method of staining a specimen fixed to a speci-men zone on the face of a slide comprising the steps of:
providing a sealed disposable staining container intended for one-time use, having a slot-like vertically open cavity therein dimensioned to receive a major portion of a single slide in close fitting relation with an end of the slide extending above the container when the slide is fully inserted in said cavity, said cavity containing a small quantity of staining liquid establishing a static liquid level therein in the absence of a slide, the depth of the static liquid level being less than the distance between the upper edge of the specimen zone and the inserted end of the slide;
removing the seal from the container;
inserting the slide into the cavity and thereby upwardly displacing the staining liquid from the static level to a dynamic level sufficient to cover the specimen zone and thereby using a relatively minimum amount of the staining liquid to stain the specimen fixed thereto;
removing the stained slide from the container; and discarding the seal, container and staining liquid.

14. The invention as claimed in claim 13 wherein the dynamic level is substantially at the top of the cavity.

15. The invention as claimed in claim 13 wherein the dynamic level is approximately twice the height of the static level.

16. The invention as claimed in claim 13 wherein the quantity of staining liquid comprises less than 2 cc.

17. A method of staining a specimen on the face of a slide comprising the steps of:
providing a glass slide;
establishing a specimen zone on a face of the slide, equidistant the slide ends;
fixing a specimen to be stained to the specimen zone of the slide face;
providing a sealed disposable staining container intended for one-time use, having a slot like vertically opening cavity therein dimensioned to receive a major por-tion of a single slide in close fitting relation with an end of the slide extending above the container when the slide is fully inserted in the cavity with the inserted slide end engaging the bottom of the cavity, the specimen zone of the slide being disposed within the cavity when the slide is fully inserted therein regardless of which end of the slide is so inserted;
providing a small quantity of staining liquid sealed within said container cavity, said liquid in the absence of a slide in the cavity establishing a static liquid level therein, the static liquid level being lower than the upper edge of the specimen zone of a slide fully inserted in the cavity;
removing the seal from the container;
inserting the slide into the cavity and thereby upwardly displacing the staining liquid from the static level to a dynamic level sufficient to cover the specimen zone and thereby using a relatively minimum amount of the staining liquid to stain the specimen fixed thereto;

removing the stained slide from the container; and discarding the seal, container and staining liquid.

18. The invention as claimed in claim 17 wherein the dynamic level is substantially at the top of the cavity.

19. The invention as claimed in claim 17 wherein the dynamic level is approximately twice the height of said static level.

20. The invention as claimed in claim 17 wherein the quantity of staining liquid comprises less than 2 cc.