CRITERION™ Pyridoxine Y Medium

Cat. no. C9120 CRITERION™ Pyridoxine Y Medium 130gm
Cat. no. C9121 CRITERION™ Pyridoxine Y Medium 500gm
Cat. no. C9122 CRITERION™ Pyridoxine Y Medium 2kg
Cat. no. C9123 CRITERION™ Pyridoxine Y Medium 10kg

INTENDED USE

Hardy Diagnostics CRITERION™ Pyridoxine Y Medium is recommended for use in determining pyridoxine concentration via the microbiological assay technique.

Dehydrated culture media is a raw material not intended for use in the diagnosis of human disease. For proper use, the product requires additional processing and ingredient supplementation before use.

SUMMARY

There are three types of assay media for use in the microbiological testing of vitamins: stock maintenance media, inoculum media to condition the organism prior to testing, and assay media for vitamin quantitation and performance testing.

CRITERION™ Pyridoxine Y Medium is an assay medium patterned after the formulation proposed by Campling and Nixon, and later modified by Hurley and Parrish, and Loy and Kline.(3-5) This formulation is commonly used in the microbiological assay of pyridoxine using Saccharomyces cerevisiae ATCC® 9080.

CRITERION™ Pyridoxine Y Medium contains all essential vitamins and nutrients to support the growth of S. cerevisiae, except for pyridoxine (vitamin B6). When prepared, the addition of pyridoxine in specified concentrations yields growth that can be measured via turbidimetric and titrimetric methods.(2)

FORMULA*

Gram weight per liter: 65.0gm/L
Dextrose 50.0gm
Amino Acid Mixture 5.23gm
Ammonium Sulfate 5.0gm
Potassium Phosphate Mono 3.75gm
Magnesium Sulfate 1.25gm
Calcium Chloride 0.61gm
Riboflavin 0.025gm
Biotin Salt 0.01gm
Inositol 0.006gm
Trace Nutrients 0.00329gm

Final pH of 2.65% solution 4.4 +/- 0.2 at 25°C.

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

STORAGE AND SHELF LIFE

Store the sealed bottle(s) containing dehydrated culture medium at 2-30°C. 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 2-8°C.

PRECAUTIONS

METHOD OF PREPARATION FOR DEHYDRATED CULTURE MEDIA

1. Suspend 65gm of the dehydrated culture media in 1L of distilled or deionized water. Stir to mix thoroughly.

2. Heat with frequent agitation and boil for 2 to 3 minutes to completely dissolve.

3. Continue stirring to maintain an even precipitation and dispense in 5.0ml aliquots into scrupuously cleaned and sterile flasks.

4. Add the standard or test samples.

5. Aseptically adjust flask volume to 10.0ml with sterile purified water.

6. Allow to boil for 10 minutes at 100ºC.

PROCEDURE AND INTERPRETATION OF RESULTS

For information on procedures and interpretation of results, consult listed references.(1-5)

LIMITATIONS

MATERIALS REQUIRED BUT NOT PROVIDED

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

QUALITY CONTROL

Hardy Diagnostics tests CRITERION™ Pyridoxine Y Medium for pH, and appearance.

User Quality Control

Physical Appearance

CRITERION™ Pyridoxine Y Medium powder should appear homogeneous, free-flowing, and white to off-white in color. The prepared medium should appear yellow to bright (neon) yellow with precipitate.

REFERENCES

1. Official Methods of Analysis. Association of Official Analytical Communities, Washington, D.C.

2. United States Pharmacopeia and National Formulary . USP-NF. United States Pharmacopeial Convention, Rockville, MD.

3. Campling J.D. and D.A. Nixon. 1954. The inositol content of foetal blood and foetal fluids. J. Physiol . 126:71-80.

4. Hurley. 1960. J. Assoc. Off. Agri. Chem. 43:43.

5. Parrish, W.P., H.W. Loy and O.L. Kline. 1955. A study of the yeast method for vitamin B 6 . J. Assoc. Off. Agri. Chem. 39:506.

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

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