Bovine serum ultrafiltrate as a general standard in clinical chemical analysis.

NUMBER OF PREVIOUS SURVEYS (1,2, 3, 4) have indicated wide discrepancies of analytic results obtained by various clinical laboratories on the same standard samples. These surveys emphasized the prevailing need for substantial improvement in this field of analysis. One attempt to do this has been through the publication of Standard Methods of Clinical Chemistry by the American Association of Clinical Chemists (5) so that the same procedure may be used by many laboratories. A second approach to narrowing the spread of results obtained by various laboratories is the use of primary standards. While such standards are available from the National Bureau of Standards for commercial materials, there has as yet been no comparable program for the clinical chemistry laboratory. A number of standards for single constituents are available from commercial sources, but there is still a great need for a multiple, stable general standard accurately analyzed and containing nearly all the constituents found in human blood. This need has been highlighted recently by Goeckel (6). Recently as a result of developments in industrial ultrafiltration technics’ it has become possible to prepare large batches of a proteinand sterol-free blood serum ultrafiltrate. This material contains all the filterable biologic constituents in the proportions usually found in human blood serum. It seemed desirable, therefore, to investigate its potentialities as a multiple general laboratory standard for clinical chemical