An example of lyophilized protein based materials not simulating patient sera

Use of reconstituted lyophilized protein based materials in the clinical laboratory is partly based on the assumption that these materials adequately simulate patients' sera. We examined several of these materials and found that certain ones do not have the same absorbancies at 340 and 380 nm as do most sera. The implication of this is examined with respect to glucose determination by the hexokinase method on a dual wave length blank subtraction instrument.