[RoTrac capillary pore membranes for laboratory filtration. II. Bacteria-free filtration]

Because of their special characteristics Capillary pore membranes (CPM) are now applied in several branches of separation techniques and analytics. Besides applications in particle analytics and microfiltration of different media capillary pore membranes can be used in microorganism separation. It was shown that RoTrac CPM can be used for bacteria free (or so called sterile) filtration. Acceptable fluxes were reached in separation of Pseudomonas diminuta (test species ATCC 19146). Membranes with pore diameters of 0.2 micron and smaller always assure a bacteria free filtrate even for a very high bacteria count of about 10(7)-10(8) bacteria/ml. In filtration of Mycoplasma arginini no sterile filtrate was obtained for a pore diameter of 0.08 micron and a high bacteria count of 3 * 10(7) bacteria/ml. The bacteria rejection by a factor of 10(5) was however remarkable. Only for 0.05 and 0.08 micron with reduced bacteria load the filtrate was bacteria free.