CRITERION™ YEAST EXTRACT

Cat. no. C7340 CRITERION™ Yeast Extract 100gm
Cat. no. C7341 CRITERION™ Yeast Extract 500gm
Cat. no. C7342 CRITERION™ Yeast Extract 2kg
Cat. no. C7343 CRITERION™ Yeast Extract 10kg
Cat. no. C7344 CRITERION™ Yeast Extract 50kg

INTENDED USE

Hardy Diagnostics CRITERION™ Yeast Extract is prepared and standardized for bacteriological use. It is an excellent stimulator of bacterial growth and is used in culture media in place of, or in addition to, beef extract.

This is a raw material intended to be used in the making of prepared media products, which will require further processing, additional ingredients, or supplements.

SUMMARY

Yeast Extract is an aqueous extract of autolysed brewer's yeast. It is usually added to culture media to provide a source of B-complex vitamins and is often used to supply these factors in bacteriological culture media. It has proved a valuable ingredient of media used for carrying stock cultures and for preparation of inocula of lactobacilli for microbiological assay of vitamins. Yeast Extract is also of value in the assay of antibiotics.

Yeast Extract has been used effectively in culture media for studies of the bacteria in milk and other dairy products. Among its many uses it has been applied in the study of bacterial flora of commercially prepared infant foods, and in the study of organisms in evaporated and condensed milk.

STORAGE AND SHELF LIFE

Store the sealed bottle containing culture medium at 2-30ºC. Dehydrated culture medium is very hygroscopic. Keep lid tightly sealed. Protect dehydrated culture media from moisture and light. The dehydrated culture media should be discarded if it is not free-flowing or if the color has changed from its original light beige.

PRECAUTIONS

METHOD OF PREPARATION FOR DEHYDRATED CULTURE MEDIA

Standard microbiological supplies and equipment such as autoclaves, incinerators, and incubators, etc., are not provided.

PHYSICAL APPEARANCE

CRITERION™ Yeast Extract powder should appear homogeneous, free-flowing, and light beige in color.

In concentrations of 0.3-0.5%, as it is generally applied, it forms a very clear solution with a pH of approximately 6.6.

REFERENCES

1. Atlas, R.M., et al. 1995. Handbook of Microbiological Media, 2nd ed. CRC Press, Boca Raton, FL.

2. MacFaddin, J.F. 1985. Media for Isolation, Cultivation, Identification, Maintenance of Bacteria, Vol. I. Williams & Wilkins, Baltimore, MD.

3. Marshall, R.T., ed. 1992. Standard Methods for the Examination of Dairy Products, 16th ed. APHA, Washington, D.C.

4. Greenberg, A.E., et al. (ed.). 1992. Standard Methods for the Examination of Water and Wastewater, 18th ed. APHA, Washington, D.C.


062916gr