Decigram quantities of pure foot‐and‐mouth disease virus from cell cultures

Baby‐hamster kidney (BHK) cell cultures grown in rolling 2‐liter Baxter bottles are used for the production of foot‐and‐mouth disease virus (FMDV) which is subsequently purified. The bottles are held securely in round wire racks (19 per rack) and rotated on a three‐tiered roller mill. The use of a strongly buffered growth medium makes changes of the medium unnecessary. A sheet of aluminum foil is used to seal the cultures. It is pressed tightly over all the bottles in a rack by means of a polyurethane foam sheeting bonded to the underside of a rigid snap‐on cover. Special equipment eliminates removing the bottles from the racks at any stage in their use. The loaded racks fit directly onto headers of a glassware washer. Spent cell growth media and virus fluids are collected by inverting an entire rack of bottles‐Current production is 400 BHK cultures (21 racks) containing 8 × 108 cells each after 6 days growth. About 344 of these cultures (18 racks) are used to grow virus. The purification process yields about 113 mg of pure FMDV per week; the overall recovery based on infectivity is 32%. The projected maximum production of purified virus in the present facilities is approximately 2.5 times greater than this amount.