Intra-erythrocytic Mg assay in the Kodak Ektachem 700 analyzer.

2154 CLINICAL CHEMISTRY, Vol. 34, No. 10, 1988 Curves for successive dilutions of a purified serum extract paralleled standard curves (data not shown). No 1,25(OH)2D was detected in a charcoal-stripped serum sample. Mean concentrations in serum from 21 healthy men and premenopausal women were 54 (SD 19) ng/L (RIA 1) and 53 (SD 18) ng/L (RIA 2), respectively. Decreased 1,25(OH)2D was observed in hemodialysis patients suffering from chronic renal failure: 15 (SD 6) ng/L and 17 (SD 6) ng/L for RIA 1 and RIA 2, respectively (n = 28). We compared the two RIA methods on the basis of results from 55 analyses obtained for healthy volunteers and patients with chronic renal failure and nephrolithiaais. Least-squares analysis yielded a satisfactory correlation: y = 1.14x 3.37; r = 0.93. Evidently, for the routine determinationof 1,25(OH)2D in serum, an RIA method based on easily accessible antibodies raised in egg yolk is a valuable alternative to the conventional procedure with use of antibodies from rabbits.