A simple technique for purifying fungal cultures contaminated with bacteria and mites

A simple technique was developed for purifying fungal cultures contaminated with bacteria and mites. It was based on the observation that the growth o f bacteria and movement of mites were confined to the upper surface of the agar. A culture contaminated with bacteria and mites was transferred to a p iece of clean paper with the upper surface facing down. Small thin pieces ( approximately 3 mm x 3 mm x 0.5 mm) of agar were removed from the exposed s urface and transferred to a V-8 agar plate. Colonies that developed from th ese agar pieces were free from bacteria and mites.