ABSTRACT
I evaluated a commercially available polyacrylamide column (Clinetics Corp.) for use in assaying for carcinoembryonic antigen. The procedure eliminates the need for dialysis and 50 samples, assayed in duplicate, may be completed in 5 h. In general, results by this technique are 1.0 microgram/L (range 0.5-2.0) lower than by the conventional dialysis method (r = 0.9876). Sensitivity approximates 0.5 microgram/L. Within-day precision for two pools of patients' plasma (n = 10) was mean = 2.29 (SEM 0.05) microgram/L with CV = 6.55% and mean = 10.61 (SEM 0.10) microgram/L with CV = 2.92%, respectively; between-day precision (n = 6) was mean = 3.90 (SEM 0.16) microgram/L with CV = 10.0% and mean = 10.1 (SEM 0.37) microgram/L, CV = 8.91%, respectively. The precentage analytical recovery of added carcinoembryonic antigen was about 80% at concentrations of approximately 8 and 12 microgram/L, 73% at 18 microgram/L.
Subject(s)
Carcinoembryonic Antigen/analysis , Acrylamides , Chromatography, Gel/methods , Costs and Cost Analysis , Dialysis/methods , HumansABSTRACT
The Corning 940 Titrator, which measures total calcium concentration by titration with [ethylenebis(oxyethylenenitrilo)]tetraacetic acid, was evaluated for use in hospital laboratory. Calcium values for patients' sera were about 0.3 mg/dl lower as measured with the Titrator than with the Technicon SMA 12/60 continuous-flow analyzer. A similar bias was evident when the results with the Titrator were compared with those from atomic absorption spectrophotometry. Agreement was better in the low range and worse in the high range. Within-day and between-day coefficients of variation on the Titrator were about 1.5% and 2.5%, respectively. We saw no interference from magnesium, phosphorus, bilirubin, or in the presence of lipemia. At extremely increased hemoglobin concentrations (500 mg/dl), there is a 5% inhibition. Titrator results for patients' urine samples correlated closely (n = 0.999) with those obtained with the SMA 12/60.
