Patent ID: 9603355
Date: 2017-03-28
CPC Classifications: A01N,A23L,A23V,A61K,C12N

Claim:
1. A method for preserving cells or tissues, comprising: suspending or immersing the cells or tissues in a cryopreservative liquid; then, freezing the cryopreservative liquid, as well as the cells or tissues therein; and keeping them for a certain period and subsequently thawing them; wherein said cryopreservative liquid is an aqueous solution comprising 1-50% by weight relative to the total weight of the cryopreservative liquid of a polyamine polymer compound comprised of a polymer of units having side-chain amino groups, said polymer of units being ε-poly-L-lysine; and 50-99 mol % of the amino groups, other than those forming amino-acid-to-amino-acid linkages, of said polymer compound are blocked with a carboxylic anhydride to form pendant moieties, each of which is linked to the main chain of the polymer via an amide linkage and has a free carboxylic acid group.