A Method for the Removal from Membrane Filters of Micro-Organisms Filtered from Water and Air

S ummary : The micro-organisms in tap water were quantitatively (99%) retained by Oxoid membrane filters. The trapped organisms were extracted from the membrane filter by a simple washing process using glass beads or a magnetic stirrer. For counts on air, the membrane filter was considerably more efficient than an ammonium alginate filter in trapping bacteria, but both techniques were equally satisfactory for moulds.