Contrast Stains

Eosin.—There are several commercial varieties of eosin, which, from the bacteriological point of view, possess very different values. Gruebler lists four varieties, of which two only are useful for bacteriological work:

Eosin, aqueous yellowish.
Eosin, aqueous bluish.

13. Eosin Aqueous Solution (Yellowish or Bluish Shade), 1 per cent.

Weigh out

Eosin, aqueous 1.0 gramme

dissolve in

Distilled water 100.0 c.c.

and add

Absolute alcohol 5.0 c.c.

Filter.

14. Eosin Alcoholic Solution, 0.5 per cent.

Weigh out

Eosin, alcoholic 0.5 gramme

and dissolve in

Alcohol (70 per cent.) 100.0 c.c.

Filter.

Safranine.—

15. Aqueous Solution.

Weigh out.

Safranine 0.5 gramme

and dissolve in

Distilled water 100.0 c.c.

Filter.

Neutral Red.—

16. Aqueous Solution.

Weigh out

Neutral red 1.0 gramme

and dissolve in

Distilled water 100.0 c.c.

Filter.

Vesuvin (or Bismarck Brown).—

17. Saturated Aqueous Solution.

Weigh out

Vesuvin 0.5 gramme

and dissolve in

Distilled water 100.0 c.c.

Filter.