Abstract: A purified cold-active beta galactosidase enzyme, specific for lactose, having a stable enzymatic activity at a temperature below 8° C. In the presence of lactose, a purified cold-active beta galactosidase enzyme, specific for lactose, having a stable enzymatic activity at a temperature ranging between 0° C. and 50° C.

Abstract: A method for separating and assaying lipoprotain to determine a degree of modification of a predetermined component in a specimen of lipoprotein, comprising the step of: determining a distance “a” from an application point of the standard sample to a fraction corresponding to the predetermined lipoprotein using an electrophoretic pattern obtained by electrophoresis of a standard sample; determining a distance “b” from the application point of the specimen to a fraction corresponding to the predetermined lipoprotein using electrophoretic pattern obtained by electrophoresis of a specimen; comparing the distance “a” and the distance “b” to determine a relative mobility “z(=b/a)” of the specimen to the standard sample, wherein the degree of modification of the predetermined component in the specimen being judged on the basis of the relative mobility “z”.