Welcome Dear Student

This blog was designed for the Biomedical Technology students at the Durban University of Technology, in Durban, South Africa. It consists of short notes on aspects that I feel that my students grapple with, and aims to provide a better explanation than that they would receive in lectures. It is also a very personal blog, where I feel comfortable 'talking' to my students.

Please email me sherlien@dut.ac.za




Search This Blog

Wednesday, April 7, 2010

MEDIA Tuts

Explain the relationship between:
Methyl red reagent; MRVP; acidic end products; pH6; Enterobacter aerogenes
Voges Proskauer; MRVP; non acidic end products; pH4; Escherichia coli

YOU NEED TO KNOW:
MRVP is the medium. It comprises 2 tests, MR and VP.
Both tests are used to differentiate between E coli and Enterobacter aerogenes.
Both orgs degrade glucose and form by products (E coli at pH4, and Ent at pH6)
Mr tests for pH4 and VP tests for pH6. In both tests a red colour is positive.
E coli end products are called acidic
Ent end products are called non acidic.
Therefore E coli is MR pos and VP neg
Enterobacter is MR neg and VP pos
Posted by at

2 comments:

  1. UnknownApril 08, 2010

    how about some answers miss p . nicholas;)

    ReplyDelete
  2. sherlienApril 08, 2010

    glad you asked Nicholas.
    MRVP is the medium, and actually takes its name from the two tests, viz MR and VP. Methyl red reagent is used to detect acidic end products, which Enterobacter does not give, as it produces end products at pH6.
    Escherichia coli produces acidic end products at pH4, which is a negative result in the VP test.
    are you more confused now?? Even I am.....

    ReplyDelete

Subscribe to: Post Comments (Atom)