Microbial contamination in pharmaceutical industry presents annoying problem to those working in the field & costs companies millions of dollars from recalls, product spoilage, rework or rejection and biofilm formation. Monitoring tools & trending of bioburden in the area of drug manufacturing is critical step to evaluate degree of microbial control in pharmaceutical manufacturing. In order to achieve good microbial control disinfectant validation program must be established. This book provides simple guide to determine antimicrobial efficacy of two selected commonly used disinfectants with environmental isolates using surface carrier test which mimic real situation of application. The most resistant species of these isolates from the same genus should be subjected to analysis to find possible nature of resistance. Antimicrobial effect of addition of selected synthetic surface active agent namely Sodium Dodecyl Sulphate to biocidal agents was examined. Neutralization procedure isa preliminary step of disinfectant qualification that do not give similar outcome for different microorganisms so failing organisms are to be excluded from this study being in need for different conditions