Development and evaluation of membrane filtration techniques in microbial analysis

Membrane filters (MFs) were used before agar was adopted by microbiologists, when Fick (1855) made nitrocellulose membranes as substitutes for animal membranes in dialysis experiments (Presswood, 1981). However, it was some time before a useful preparation method was developed (Zsigmondy and Bachmann, 1918), leading to commercial production by Sartorius-Werke AG (Gottingen, Germany). Before World War II, MFs were used primarily for sterilization. However, devastation of laboratories and contamination of water supplies by bombing raids led to their application for determining water safety by German hygiene institutes. After the war, the first MF methods for culturing organisms were published (Muller, 1947a, Muller, 1947b).