“…Physiological and meta bolic aspects of stored blood have been in vestigated [2], and the stability of some enzymes has been studied by several work ers [3, 4, 6, 10], In the present study, ac tivities of red cell glycolytic enzymes, glucose-6-phosphate dehydrogenase, 6-phosphogluconic dehydrogenase, glutathione re ductase, glutathione peroxidase, adenylate kinase, adenosine deaminase, and acetyl cholinesterase were essentially unchanged, except for triose phosphate isomerase, after 8 months of storage. Concerning red cell PK, this result is in accord with reports that the activity did not change during 3 weeks [6], and 19 weeks [10] of storage in liquid nitrogen. In addition, kinetic and electro phoretic properties of PK Tokyo I, which is…”