MTT Positivity: Can Contamination show MTT+

[Mariappan, Muthu Marthanda Rajan]

I am a Tissue Engineering Researcher. I have been growing some cells in 
a polymer scaffold. As controls, I had been using plain plymer scaffolds 
without Cells.
	To quantitate the cell growth, I tried using the MTT assay.
But the coltrols show a very strong reaction. I am yet very unclear 
whether a false +ve MTT can be because of the Matrix scaffold itself or 
whether I am dealing with something else.
	I was wondering whether Contaminations can cause a +ve MTT., Of course 
I have taken precautions like Ethlylene Oxide sterilisation etc.,... but 
still, is it possible to get a +ve MTT with bacterial or fungal 
contaminations.
_rajan
mariappan at utsw.swmed.edu