MTEC Cell Culture Unit has been accepted as an accredited laboratory complying with the ISO/IEC 17025: 2005 in the field of medical devices testing and microbial testing. Due to its annually audit surveillance and extension of accredited certification, the Unit needs to carry out an interlaboratory comparison activity for its 2 cytotoxicity test methods and 3 microbial test methods. The testing results from all laboratories will be compared and reported. Systematic assessment of factors influencing the results, testing performance and personnel competence will be determined. The other activity, the Unit will develop 2 testing methods (1) MTT cytotoxicity assay as an alternative method for cytotoxicity screening of medical devices and (2) a modified ASTM G21 method for evaluation the fungal resistance of synthetic polymeric materials. The optimized factors such as spore suspension, growth medium, contact time and the suitable condition for selected materials will be determined. Also the rates of colonization in the materials by the fungal growth will be compared. Further investigation of the modified method will be shown.