Cat. no. Z20 Mineral Oil, Heavy Grade 20ml
Cat. no. Z79 Mineral Oil, Heavy Grade 15ml
Cat. no. Z80 Sterile Mineral Oil, Heavy Grade 150ml


Hardy Diagnostics Mineral Oil is used as a sealant to create an anaerobic environment for biochemical tests such as decarboxylase and oxidation and fermentation reactions. These products are not for use in surgical or patient applications. These Mineral Oils are strictly for laboratory use.


Certain biochemical tests, such as decarboxylation and deamination reactions, rely on the organisms ability to metabolize specific substrates in the test media under anaerobic conditions. Mineral oil overlay protects the surface of the media from the air, thus preventing false reactions at the top of the tube. Similarly, an oil overlay in one of two identically inoculated tubes of oxidation/fermentation media allows differentiation of fermenters, oxidizers and non-oxidizers.


Mineral Oil, Heavy 100%


Storage: Upon receipt store at 15-30ºC. These products should not be used if there are any signs of contamination, deterioration, or if the expiration date has passed. Product is light and temperature sensitive; protect from light, excessive heat, moisture, and freezing.


Warning: Mineral Oil is highly flammable. Keep away from heat and flames.


Specimen Collection: This product is not intended for primary isolation of patient specimens. This product is used in conjunction with other biochemical tests to identify cultures of isolated organisms.

Method of Use: Overlay tubed media for biochemical testing, (i.e. Decarboxylase, Cat. no. Y41-Y44 and OF Media, Cat. no. Y51-Y71) with one centimeter of Mineral Oil. Use aseptic technique. Consult appropriate references and media technical inserts for detailed descriptions of usage and interpretation of results.(1-4)

If using mineral oil for commercial identification strips, such as API®, consult the manufacturer's literature.


Medium and light weight Mineral Oils may allow permeation of oxygen.

Mineral Oil which has become acidic can contribute to false-positive results.


Standard microbiological supplies and equipment such as loops, pasteur pipets, incinerators, and incubators, etc., as well as serological and biochemical reagents, are not provided.


The grade of Mineral Oil used in this product is such that it is free of any impurities that could interfere with test results.

User Quality Control


Mineral Oil should appear clear and colorless.


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

2. Howard, B.J., et al. 1987. Clinical and Pathogenic 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. Biochemical Tests for Identification of Medical Bacteria,, Lipincott Williams & Wilkins, Philadelphia, PA.

6. Quality Assurance for Commercially Prepared Microbiological Culture Media, M22. Clinical and Laboratory Standards Institute (CLSI - formerly NCCLS), Wayne, PA.

API is a registered trademark of bioMeriuex, France.