Immunology Diagnosis

How do you work out what Mycoplasma test method is best for your samples?  This article (see above link) answers that question for pharma labs.  If you are in a  research lab, my answer is:  assess the quality of the method and use that in your decision.  Price and quality may be poles apart.

Just because everyone should know this information, here are the three questions I use to assess quality for Mycoplasma test methods.

Question One – how sensitive?  Every kit or test lab should be able to give you an objective measure of their method’s sensitivity.  Sensitivity is usually measured in cfu/mL (colony forming units per mL), or ng/mL with a PCR kit.  The lower the number detected, the more sensitive that method should be.  Compare the different test kits on the market and you will immediately see there are some large differences.

Question Two – how many species?  There are many different Mycoplasma species, one reason why testing can be difficult.  Your test method should at least be able to detect the six species that commonly appear in cell cultures.  But the more the better.

Question Three – can you detect your own control?  If you test for Mycoplasma routinely, it won’t be long before you find a positive sample.  Aliquot the medium from that sample into a set of tubes and freeze it (in its own box) at -80C to give yourself a set of positive controls.  Alternatively, if you are looking at a PCR-based method, purchase DNA from one or more of the common species.  Of course most kits on the market include a control, but that’s only one species.  Your own sample will give an even better idea of how good the method truly is.

For another excellent review on Mycoplasma, see:  http://www.ncbi.nlm.nih.gov/pubmed?term=19003295