Biology/microbiology
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Question
Hello, I'm Mia.
I know that catalase test not done directly on blood agar cause it will give false positive but why and how it happen?
Hi Mia: Thanks for your question.
The reason catalase tests are not done on blood agar is that red blood cells (erythrocytes) contain the enzyme catalase. The reaction will then give a false positive because you will see the catalase in RBC reacting, instead of the catalase in the bacteria.
Here's a link:
http://www.ncbi.nlm.nih.gov/pubmed/8608252
http://en.wikipedia.org/wiki/Catalase
Hope this helps. Write back if you have more questions.
FM Rollwagen, PhD
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Answers by Expert:
Florence M Rollwagen
Expertise
I can answer questions in biology, microbiology and immunology on the undergraduate or graduate level. I can also address medical and health concerns regarding alternative medicine, autoimmune diseases (lupus, MS) liver disease and intestinal problems.
Experience
I have over 20 years experience in research and teaching at the medical/graduate level, and 5 years teaching college biology and microbiology. My expertise is in microbiology and immunology, specifically the biology of cytokines and soluble immune response modifiers. I also carried out original research in blood substitutes and shock/trauma.
Organizations
American Association of Immunologists (AAI)
American Association for the Advancement of Science (AAAS)
Publications
Journal of Experimental Medicine, Journal of Immunology, Cytokine, Shock, Experimental Hematology
Education/Credentials
BS biology 1966
MS biology 1968
PhD immunology 1979
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