CRITERION™ SKIM MILK POWDER

Cat. no. C6960 CRITERION™ Skim Milk Powder 200gm
Cat. no. C6961 CRITERION™ Skim Milk Powder 500gm
Cat. no. C6962 CRITERION™ Skim Milk Powder 2kg
Cat. no. C6963 CRITERION™ Skim Milk Powder 10kg
Cat. no. C6964 CRITERION™ Skim Milk Powder 50kg

INTENDED USE

Hardy Diagnostics CRITERION™ Skim Milk Powder is used for preparing microbiological culture media and for differentiating organisms based on coagulation and proteolysis of casein.

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

Skim Milk is soluble, spray-dried milk. When prepared in a 10% solution, it is equivalent to fresh skim milk.

Skim Milk can be used to prepare Skim Milk Agar for detecting proteolytic microorganisms in foods, including dairy products. It can also be used to prepare litmus milk, a differential test medium for determining lactose-fermentation and for detecting proteolytic enzymes that hydrolyze casein (milk protein) and cause coagulation (clot formation). It is commonly added to media to enhance the growth of Mycobacterium tuberculosis and Corynebacterium diphtheria.

FORMULA

Gram weight per liter: 100.0gm/L
Skim Milk 100.0gm

Final pH 6.3 +/- 0.2 at 25ºC.

* Adjusted and/or supplemented as required to meet performance criteria.

STORAGE AND SHELF LIFE

Store the sealed bottle(s) containing dehydrated 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 white to off-white.

Store the prepared culture media at 2-30ºC.

PRECAUTIONS

METHOD OF PREPARATION FOR DEHYDRATED CULTURE MEDIA

1. Suspend 100.0gm of the Skim Milk Powder in 1 liter of distilled or deionized water.

2. Heat to boiling and mix to dissolve completely.

3. Sterilize in the autoclave at 121ºC. for 15 minutes.

PROCEDURE AND INTERPRETATION OF RESULTS

For information on procedures and interpretation of results, consult listed references or refer to the prepared media Instructions for Use (IFU) for Cat. No. G138.

LIMITATIONS

Skim Milk supports the growth of many microorganisms. Perform microscopic examination and other biochemical tests to identify isolates to the genus and species level, if necessary.

MATERIALS REQUIRED BUT NOT PROVIDED

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

QUALITY CONTROL

Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Clostridium perfringens
ATCC ® 13124
A 1-7 days 35°C Aerobic Growth; stormy fermentation
Enterococcus faecalis
ATCC ® 29212
A 1-7 days 35°C Aerobic Growth with acid clot and clearing

User Quality Control

PHYSICAL APPEARANCE

CRITERION™ Skim Milk powder should appear homogeneous, free-flowing, and white to off-white in color. The prepared media should appear opalescent, and white in color, after warming. However, after autoclaving the same solution should appear opaque, and off-white to beige in color.

REFERENCES

1. Jorgensen., et al. Manual of Clinical Microbiology, American Society for Microbiology, Washington, D.C.

2. Tille, P., et al. Bailey and Scott's Diagnostic Microbiology, C.V. Mosby Company, St. Louis, MO.

3. Isenberg, H.D. Clinical Microbiology Procedures Handbook, Vol. I, II & III. American Society for Microbiology, Washington, D.C.

4. Koneman, E.W., et al. Color Atlas and Textbook of Diagnostic Microbiology, J.B. Lippincott Company, Philadelphia, PA.

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


ATCC is a registered trademark of the American Type Culture Collection.

062116gr