Membrane Filter

Membrane filtration is a process of filtering liquid by passing it through a membrane (made of cellulose acetate or mixed cellulose esters etc.) which has pores small enough to hold selected microbes and large enough to let the liquid pass through. The pore size can be from 0.22 to 0.45 micrometer. The process is useful in cleaning the liquid and capturing the bacteria. The filters are generally incubated for some time to observe the growth of microbial colonies on them and in some cases they are directly transferred onto the plate having the culture medium. A filter holder is required to hold a certain volume of liquid until it passes through the membrane. Characteristics • Made of durable plastic. • Autoclavable. • 500 to 1000 mL capacity. • Some designs have a tool to collect filtrate as well.