grammes

and dissolve in

Distilled water 100.0 c.c.

BLOOD STAINS

When watery solutions of medicinal methylene blue and water soluble
eosins are mixed a precipitate is formed which is soluble only in
alcohol, and solutions of this precipitate impart a peculiar
reddish-purple colour to chromatin. This compound was first used by
Romanowsky to demonstrate malarial parasites, but various modifications
are now employed for staining blood films generally, and also for
bacteria and protozoa. The best modifications of the original Romanowsky
are those of Jenner and Leishman--Jenner being most suitable for the
histological study of the blood, and Leishman for the demonstration of
protozoa.

~Jenner's Stain.~--

A. Weigh out:

Eosin aqueous yellow 6.0 grammes

Dissolve in

Distilled water (non-alkaline) 250 c.c.

This will make a thick solution.

B. Weigh out:

Methylene blue (medicinally pure) Hoechst 5.0 grammes

Dissolve in

Distilled water (non-alkaline) 250 c.c.

1. Add B to A very slowly, stirring all the time. A viscous precipitate
forms which frequently loses its viscosity when heat is applied. (This
explains the necessity of mixing slowly).

2. Evaporate slowly in a porcelain basin, stirring occasionally, on a
water bath at 55 deg. C. When a paste begins to form scrape and break up
occasionally. (On no account must the paste be allowed to fuse.)

3. Grind the resulting mass into an amorphous powder.

4. Weigh out:

Amorphous powder 0.5 grammes

Dissolve in

Methylic alcohol (Merck's puriss, for analysis) 100 c.c.

Allow time for true solution. (About three days is sufficient.)

METHOD.--

1. Prepare film, dry, but _do not fix_.

2. Flood the unfixed film with the stain, allow it to act for 3 minutes
(the methylic alcohol of the stain fixes the film).

3. Pour off the stain and wash in distilled water until the film
presents a pink colour.

4. Dry and mount.

~Leishman's Stain.~--

_A._ Weigh out:

Methylene blue (medicinal) 1 gramme

Dissolve in

Sodium carbonate, 0.5 per cent. aqueous solution 100 c.c.

Keep at 65 deg. C. for 12 hours in either a hot incubator or a water-bath;
then stand in dark place at room temperature (20 deg. C.) for ten days.

_B._ Weigh out:

Eosin, extra B. A. 0.1 gramme

Dissolve in

Distilled water 100 c.c.

1. Mix the two solutions A