Contamination is a pervasive cell culture problem and sometimes with very serious consequences. Bacteria, fungi, mycoplasma and yeast are the common sources of biological contamination. Sterility testing is used to demonstrate the presence or absence of contaminating microorganisms. It is very important during the manufacture of biologics, pharmaceuticals and medical devices. Sterility testing has been required as an official test for pharmaceutical articles. Reliable and adequate sterility testing results are critical to quality assurance issues.