Eleven commercial kits for serum ferritin have been compared. Seven kits used RIA and four IRMA methodology. Seven kits used human liver ferritin, two human spleen ferritin and two undefined human ferritin as standard material. Incubation times varied between 30 minutes and 36 hours. Only four kits gave normal ranges determined with the kit in question. All values were compared with the kit in ...

specificities of 0.825 (confidence interval, 0.677– 0.916) and 0.965 (0.851– 0.995), respectively. We found that when RCVs from creatinine and urate combined were used to predict crises, the FP probability was reduced and there was a considerable increase in diagnostic specificity. The methodology used in this work pointed out the need to improve laboratory reports (13) as follows: • Include th...

We have developed a "sandwich"-type immunoradiometric assay for corticotropin (ACTH), with a detection limit of 2 ng/L. Two antibodies are used: a mouse monoclonal antibody directed against ACTH[1-17] and labeled with 125I; and a purified polyclonal goat antibody directed against ACTH[34-39] and conjugated to biotin. We could separate 125I-labeled antibody bound to ACTH from 125I-labeled antibo...

Newly developed IRMAs to measure the plasma concentrations of renin and prorenin were validated for clinical use and compared with a classical enzyme kinetic assay. The IRMAs involve two monoclonal antibodies, one that reacts equally well with renin and prorenin and one that recognizes renin well but prorenin only minimally. Prorenin reactivity with the second antibody was enhanced by adding th...

BACKGROUND The new Elecsys chemiluminescence assay for measurement of homodimeric sex hormone-binding globulin (SHBG) was designed for use with undiluted serum, in contrast to other methods that require predilution. During assay development, unexpected calibration difficulties were observed that were attributable to particular biochemical properties of the highly concentrated SHBG in solution. ...

Antibodies were purified by affinity chromatography and radioiodinated by a conjugation method for use inthe immunoradiometric assay for serum ferritin. These procedures are simpler and more reproducible than those described earlier, and the radiolabeled preparations were usable for at least 13 weeks.

Inununoassays based on chemilunlinescent acridinium salts are highlysensitive, robust, and simple (1) but have not been demonstrated in a microplate format because of the lack of suitable luminometers with “on-board” reagent injection systems necessary for quantifying rapidchemiluminescent reactions. We report our initial studies on a two-site immunochemiluminometric assay (IcMA) for thyrotropi...