Evaluation of the Stability of Hemoglobin in Storage by Electron Spin Resonance

摘要

A series of hemoglobin (Hb) samples were received from LAIR. They were stored in two types of containers at 4 C and one set was frozen at dry ice temperatures. These samples were analyzed for metHb and hemichrome content as a function of storage time using ESR. The samples stored in sealed glass bottles at 4 C had a very uniform increase in metHb over the period of the study (17 months). This rate of increase appeared exponential in nature. The frozen samples, which were also stored in glass bottles, showed no increase in metHb over the period during which they were frozen. However, upon thawing, these samples gave an increase in metHb at a rate similar to those samples which had never been frozen. The samples, which had been stored at 4 C in a blood-pack, had a rate of increase in metHb identical to those stored in glass bottles. The total hemichrome content of the storage samples is estimated at 30% to 45% of the metHb content for samples A and B, and 45% to 60% for samples C, D and E. However, all the hemichromes are in simple conformational equilibria with the metHb. Both the metHb and all the observed hemichromes can be converted in vivo back to Hb, and they are not expected to affect the viability of the solution as a resuscitation fluid.