Substantially pure chymosin is separated from rennet extracts by contacting a liquid extract with an anionic exchange medium, preferably a diethylaminoethyl (DEAE) cellulose resin packed in a liquid chromatographic column, either as a static bed or stirred bed. The rennet extract and resin are conditioned so that the resin selectively binds pepsin and chymosin passes through the resin bed and is recovered from the liquid extract from the column. The bound pepsin is periodically removed from the resin by passing a suitable eluant through the resin bed.

A coagulant composition for the cheese industry, whose purpose is to coagulate milk in the preparation of cheeses, is produced by mixing a first coagulant enzyme of fungic origin and non-coagulant proteic extracts from bovine reed. The composition may also contain a second proteolytic enzyme, extracted from another microbial strain or from bovine pepsin.

Cold-and cryo-preservation solutions for tissue slices include a limited amount of glucose. The solutions provide extended cold storage of the slices without a loss of viability. The solutions also allow cryopreservation of the slices, so that the slices may be stored until needed and then thawed, cultured, packaged and distributed.