title: Column chromatography and immunoassay compared for measuring the isoenzymes of aspartate aminotransferase in serum.
abstract: We compare a column-chromatographic method and a homogeneous immunoassay method for separately measuring the mitochondrial and cytoplasmic isoenzymes of aspartate aminotransferase. Analytical recovery for the two methods averaged 102% (SD, 2%) and 103% (SD, 4%), respectively, for 11 pools prepared by adding the purified isoenzymes to serum and 102% (SD 8.9%) and 89% (SD, 8.1%) for 26 unaltered specimens of human serum. In comparing the results of the immunoassay method (y) to the chromatographic method (x), our measurements agreed closely for the mitochondrial (y = 0.947 X + 7, r = 0.9991, standard error of estimate = 2.9 U/L) and cytoplasmic (y = 0.92x-6, r = 0.9995, standard error of estimate = 2.1 U/L) isoenzymes in pools prepared from the purified isoenzymes. Similar measurements of the 26 human serum specimens yielded the following results for least-squares evaluation; cytoplasmic isoenzyme y = 1.03x-11, r = 0.994, and standard error of estimate = 6.0 U/L; mitochondrial isoenzyme y = 0.75x+0, r = 0.927, and standard error of estimate = 3.9 U/L.
mesh_terms: D001219:Aspartate Aminotransferases / Q000097:blood*; D002852:Chromatography, Ion Exchange / Q000379:methods; D003593:Cytoplasm / Q000201:enzymology; D006801:Humans; D007118:Immunoassay; D007527:Isoenzymes / Q000097:blood*; D007700:Kinetics; D008928:Mitochondria / Q000201:enzymology
chemical_list: D007527:Isoenzymes; D001219:Aspartate Aminotransferases