A laboratory guide in elementary bacteriology / by William Dodge Frost.

Date:
1903
Catalogue details

Licence: In copyright

Credit: A laboratory guide in elementary bacteriology / by William Dodge Frost. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    a piece of sheet iron or in hot air sterilizer for one hour at about 200° C. They are best kept in a clean Petri dish and handled with forceps. (Novy). Old slides and covers having balsam on them should first he dropped one by one into a cleaning solution (potassium bichromate 60, sulphuric acid 60, water 1,000), and boiled for one-half hour and then treated as above. Special Directions. Clean ]/2 oz. of cover-glasses and place them in a clean Petri dish. EXERCISE 17. PREPARATION OF STAINING SOLUTIONS. Ceneral Directions. The dyes most useful for staining bac- teria are the basic anilin dyes which come in poivdered or crystal- line form. (Gruebler’s dyes are standard). Those in most com- mon use are Fuchsin, Methylen blue, Gentian violet and Bismarck brown. They keep in powdered form, with perhaps the exception of Methylen blue, but because of greater convenience and equally good keeping qualities, saturated alcoholic solutions are kept in stock. These are made by adding the dry dye to 95% alcohol to saturation and filtering. This form can not be used for staining bacteria. The following solutions are required to begin work with: 1. Aqueous solution of Gentian violet. Saturated alcoholic solution of Gentian violet 2.5 ce. Distilled water 47.5 cc. 2. Saturated aqueous solution of Bismarck brown. 3. Ziehl’s carbol-fuchsin. Saturated alcoholic solution of Fuchsin ' 5 cc. Solution of carbolic acid (5%) 45 cc. 4. Loeffler’s Methylen blue. Saturated alcoholic solution of Methylen blue 15 cc. Potassium hydrate (1:10,000)1 50 cc. 5. Ehrlich’s Anilin Oil Gentian violet.2 Saturated alcoholic solution of Gentian violet 6 cc. Absolute alcohol 5 cc. Anilin water 50 cc. 1 This dilution can be readily made by taking 1 cc. of a 10% potassium hydrate solution, making this up to 100 cc., then taking 5 cc. of this and making it up to 50 cc. 2 Some prefer Sterling’s anilin oil Gentian violet. Solution A., 2 gms. anilin oil and 8 gms. 95% alcohol; Solution B., 1 gm. gentian violet and 90 cc. of distilled water; mix A. and B. and filter. This stain remains good for a long time.