TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Method: The pre-coating is done under the differential pressure of 2-3 psig. The pre-coat layer thickness varies from 1.5-15 mm including body feed or otherwise. The carrier liquid is water or suitable solvent. In post pre-coating, the filter vessel is drained to remove entrapped carrier solvent/water/clear liquid product by purging of clean compressed air/nitrogen to dewater the pre-coat layer. The filter stack is stationary during filter filling, pre-coating, body-feeding, filtering, dewatering, hold up/heel filtration, filter draining and wet cake biomass deactivating. The filter plate stack is rotated after filtering the feed batch to dislodge the wet cake or slurring it for discharging. The wet cake is slurried by spraying water before dislodging. The circulation of HDMF broth is continued till filtrate clarity is achieved but not greater than 15 minutes. The inlet valve on the guard filter is opened to allow the filtrate to pass through guard filters for trapping accidental release of leaked turbid filtrate to the filtrate receiving tank once the filtrate is clear. Preferred Components: The pre-coat powders sterile grade is chosen from diatomite, perlite and cellulosic origin. The CIP comprises cleaning of filter by filter stack rotation, jet sprays of hot water/steam using spray header and introducing clean air/nitrogen/dry steam from filtrate side to ensure perfect cleaning. The spray header comprises jet sprays positioned above each filter plate. The spray header is in rotatable position to give more flexibility in cleaning. In the rotary leaf filtration system, the backwashing of the filter is done by introducing water/solvent or air/nitrogen/steam at 0.15 kg/cm2 pressure from filtrate side to assist opening of clogged filter media pores. The SIP-sterilizing in position comprises introducing steam at 0.15 kg/cm2 or more at 121 degrees C followed by blowing dry steam air/nitrogen for final drying before next batch. EXAMPLE - No suitable example given.