Red-Cell Enzyme Activities and Properties of Mutant Pyruvate Kinase after 1-Year Storage in a -80°C Freezer

Abstract

Red cells from 5 healthy adults and an unstable mutant pyruvate kinase (PK), PK Maebashi, were stored for 12 months in a -80°C freezer. With an exception of triose- phosphate isomerase and phosphoglycerate kinase activities, normal red-cell enzyme activities remained essentially unchanged. Mutant PK was characterized by the methods recommended by the International Committee for Standardization in Haematology (ICSH). Normal control and PK Maebashi remained essentially unchanged in their characteristics after storage in a -80°C freezer for 12 months. These results indicate that the red cells stored over a long term in a -80 °C freezer can be used for the study of unstable mutant PK.