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STAINS 



solution A drop by drop until the mixture is dark blue 

 and has lost its eosin tint To stain, float blood-films 

 face down on this mixture for 5 to 10 minutes. Noet- 

 zel's Method for capsules of coccidia: Treat the 

 coccidia with a I % solution of potassium hydroxid, 

 stain with gentian-violet, and decolorize in acetic acid. 

 Noir colin, the anilin black of Lightfoot; recom- 

 mended by Luys for the central tissues. Stain for 3 or 

 4 minutes in a 0.1% solution. Nooske Stain for 

 eosinophile granules: (a) Add one drop of caustic 

 potash to 20 c.c. of a 1% aqueous solution of Lyons 

 blue, boil for 5 minutes, and dilute with 20 parts of 

 alcohol. {b) In the same way prepare a solution of 

 bismarck brown. Mix 30 c.c of a with 5 c.c. of b, 

 add 25 c.c. of alcohol, and make up to 100 c.c. with 

 distilled water. Stain in the warmed mixture, wash 

 in acid alcohol, differentiate in a mixture of equal 

 parts of anilin, alcohol, and distilled water; alcohol, 

 xylol, balsam. Obersteiner's Method for the demon- 

 stration of degenerative changes in the axis-cylinder: 

 This is the same as Platner's method for neurokeratin. 

 See Staining of Nerve Tissue, Table of Stains (Illus. 

 Diet.). Ohlmacher's Formalin Solutions. 1. 

 Formalin-fucksin. Dissolve I gm. of fuchsin in IO 

 c.c. of absolute alcohol and add 100 c.c. of 4% forma- 

 lin 2. Formalin-gentian-vioUt. Saturated alcoholic 

 solution of gentian and 4J6 formalin in the proportion 

 of \ : IO. 3. Formalin methylene-blue. One gm. of 

 the pigment to loo c.c. of 4% formalin. 4. Forma- 

 lin methyl-violet j B. Prepare like formalin gentian- 

 violet. 5- Formalin-safranin O. Saturated solution 

 of the pigment in 4$ formalin. This gives a plasma 

 stain like eosin. Sections are said to stain in these 

 solutions in 30 seconds. Ohlmacher's Liquid : 

 Absolute alcohol 80 parts, chloroform 15 parts, glacial 

 acetic acid 5 parts, sublimate to saturation (about 

 20%). A medium of high penetration and rapid ac- 

 tion. Small objects are fixed in from 15 to 30 minutes; 

 large objects — as a human cerebral hemisphere — in 24 

 hours. Wash in iodin-alcohol. See Zenker's Fluid. 

 Ohlmacher's Picrofuchsin : Dilute a saturated 

 solution of picric acid with an equal volume of water 

 and add 0.5*7 of acid-fuchsin. Used as an alterative 

 with gentian-violet. Opal Blue, a rosanilin deriva- 

 tive, similar to anilin blue. Oppel's Method for the 

 demonstration of lattice fibers in alcohol material : 

 Transfer the object from the alcohol to a 10% solution 

 of yellow potassium chromate ; after 24 hours to silver 

 nitrate solution. See, further, the method of Bdhm. 

 Osmication Reaction of the fatty granules within 

 the cells of tissues undergoing fatty degeneration: 

 This reaction is obtained by fixing the tissue in the 

 liquid of Flemming and staining the sections in safranin ; 

 avoid using turpentine, xylol, ether, and creasote, for 

 these reagents dissolve osmicated fat, which is not 

 affected by alcohol, chloroform, and clove oil. Cf. 

 t III and Muhaelis* Jfetaoa'. Osmond's 

 Method for polishing and etching metal sections: 

 Polish on parchment with calcium sulfate dissolved in 

 an infusion of licorice root; etch with an alcoholic 

 solution of iodin containing 1.25 <£ each of iodin, 

 potassium iodid, and water. When the color of the 

 iodin has faded, wash in water, then in alcohol, and 

 dry in a blast of hot air. The etching may also be 

 done with nitric acid. To preserve the section cover 

 it with a solution of paraffin in benzene ; the coating 

 of paraffin left by evaporation of the solvent may at 

 any time be dissolved off with benzene. Overton's 

 Method. 1. For fixing with iodin: Heat crystals 

 of iodin in a test-tube and pour the vapor over the 

 objects, arranged on a slide ; warm the slide to 40 C. 

 to evaporate the iodin. 2. For attaching small, unem- 



bedded objects to the slide or cover-glass : Pour over 

 the object a drop of a very thin solution of celloidin ; 

 tilt to drain off the excess and harden in 805^ alcohol. 

 Pappenheim's Method. 1. For medullated colored 

 blood-cells : Put traces of crystal cement on a slide, 

 at points corresponding to the middle and the corners 

 of a cover-glass, and by means of a delicate sable 

 brush add the merest trace of neutral-red ; over this 

 place the cover-glass charged with blood; seal the 

 edges. The pigment is distributed by means of the 

 blood-plasma. 2. For smegma bacillus : The method 

 is the same as Czaplewski's for tubercle bacilli, except 

 that coraliin is used instead of fluorescein. See Stain- 

 ing of Microorganisms , Table of Stains (Illus .Diet. . 

 Parker-Floyd Mixture, a fixing medium for the cen- 

 tral nervous system. Six volumes of- 95^ alcohol 

 and 4 volumes of 0.025^ formalin (2 c.c. of 40^ 

 formalin to 98 c.c. of water). A sheep's brain will 

 harden in a week or ten days. Parker- Howard 

 Method for sterilizing slides and cover- glasses: Drop 

 them one by one in an enameled iron pan containing 

 \ofc solution of chromic acid and boil for 20 minutes. 

 Wash in water, then in 85^ alcohol, then in absolute 

 alcohol. Patten's Method for orientation of small 

 objects : Cut a strip from paper ruled with two sets 

 of raised lines at right angles to each other. Place 

 small drops of a mixture of celloidin and clove oil, 

 having the consistence of honey, at suitable intervals 

 on one of the lengthwise lines. Clear the objects in 

 clove oil and place one on each drop, so that the cross- 

 lines are parallel to the planes in which sections are to 

 be cut. Put the paper with the objects in turpentine, 

 which washes out the oil and leaves the objects firmly 

 attached to the paper. Infiltrate with paraffin and 

 embed in the usual way. Cool, trim, and strip off the 

 paper. This surface will be marked by the embossed 

 orienting lines. Peirce's Method for labeling slides : 

 Paint the end of the slide with a coat of thin balsam ; 

 use preferably a drawing ink for writing on the balsam. 

 W ben dry this label may be made permanent by a 

 second coat of thin balsam. A white background 

 ■ makes the writing appear more distinct. Perl's Re- 

 action, a test for the presence of iron in pigmentary 

 degeneration. Treat the fresh tissue or that fixed in 

 4J& formalin for from 2 to 5 minutes with 2$P solution 

 of potassium ferrocyanid, then for the same time with 

 I f c hydrochloric acid, and wash in distilled water. If 

 Muller's fluid is used, the test must be made with hot 

 hydrochloric acid. Petroff s Method for staining 

 erythrocytes in tissue section: Fix in Muller's or 

 Orth's medium or in formalin; embed in paraffin and 

 cut very thin sections. Dissolve out the paraffin with 

 xylol and wash in alcohol and then in water. Stain 

 10 or 15 minutes in bismarck brown (saturated solution 

 in 1% acetic acid) or 30 minutes in borax or lithium 

 earmin, following borax-carmin with acid alcohol. 

 Wash in water and stain for 10 or 15 minutes in 20^ 

 malachite green (dissolved in alcohol and diluted with 

 5 volumes of water) ; wash, and stain in Van Gilson's 

 picrofuchsin or in saturated aqueous solution of picric 

 acid diluted with 4 or 5 volumes of water. Petrone's 

 Method for staining the nuclei of erythroblasts : Treat 

 the film with Lugol's solution, then with gold chlorid 

 or silver nitrate. The reaction is supposed to depend 

 on the iron in the nuclei and is said to demonstrate 

 that they contain less iron in anemia than in health. 

 Pfaundler's Method for numeration of bacteria: 

 Mix 3 loopfuls of a 24-hour culture with a half test- 

 tubeful of bouillon ; fill the pipet of the white blocd- 

 cell counter of the Thoma-Zeiss apparatus up to the 

 I. o mark with blood and dilute up to the 11.0 mark 

 with the emulsion of bacilli ; agitate and blow the 



