Modification of the o-cresolphthalein complexone method for determining calcium.

(b) by adding antiserum to the B sub-unit of CK to a portion of a patient's sample and the control, then electro-phoresing the untreated and treated aliquots in adjacent positions on the same agarose film. On inspecting the films before enzyme substrate was added, we would see fluorescent bands cathodal and anodal, adjacent to but distinct from the position where the BB isoenzyme would be expected to appear, as judged from the results for the control and as confirmed by the position of a fluorescent band adjacent to CK-BB in those sera in which CK-BB was detectable. Whether CK-BB is present in the serum of patients who are in renal failure or whether there is an artifact that has been misinterpreted as CK-BB has been the subject of several reports (2-5, 7-12). The central question is whether or not the usual electrophoresis can resolve the albumin artifact from CK-BB. Whether for cellulose acetate, agar, or agarose electrophoretic systems, the conclusions are conflicting. We found that CK-BB can be detected in the serum of 8.3% of our sample of patients in chronic renal failure. In addition, naturally fluorescent bands were present in each sample, consistent with previous reports; the presence of two such bands consistently in each sample has not been reported previously, to our knowledge. Under the conditions we use, however, the naturally fluorescent bands not only migrate differently from CK-BB (6), but, being yellow-green, are clearly distinguishable from the blue-white fluorescence of the CK isoen-zymes. We emphasize that visual inspection and the use of a human contol reduces the possibility that the artifact might be misinterpreted as CK-BB. We believe that the use of scanning densitometer patterns without visual inspection of electrophoretic patterns may result in some misinterpretation of peaks in cellulose acetate and agarose systems, and that this may partly account for the discrepant reports among investigators. We also have noted that a control of nonhuman origin will have small but detectable differences in electrophoretic mobility of CK isoenzymes. In theory, an isoenzyme in such a control would be matched to an artifact in a patient's sample. Regardless of the support medium used, the naturally fluorescent bands appear. We encourage direct visual inspection for the purpose of identifying CK-BB as well as CK-MB (6). detection of creatine kinase isoenzyme CK-1 in serum.phoretic identification of the brain isoenzyme of creatine kinase following treatment with anti-BB antisera. P., Creatine kinase …