Hydrolysis of 3-acetoxymethyl cephalosporins by lysed whole blood.

Cephalosporins having a 3-acetoxymethyl group are hydrolyzed to the corresponding desacetyl derivative by lysed whole blood but not by plasma or serum. When bioassays for this important class of cephalosporins must be run in whole blood or on tissues containing whole blood, steps should be taken to assure that the influence of the whole blood on the bioassay is properly interpreted.