ABSTRACT
We describe a kinetic immunonephelometric method for the determination of fibronectin in human plasma, used with the Beckman ICS rate nephelometer. The method is rapid and cost-effective. Two commercially available controls stated by the manufacturer to contain 200 and 295 mg/L were found to contain 198 and 290 mg/L, respectively. Mean analytical recovery was 104%. Within-run precision (CV) for normal samples was 3.8%, between-day precision 5.1%. For samples containing subnormal concentrations of fibronectin, these figures were 3.8% and 6.7%, respectively. Results by the method described here agreed and correlated well with those by a commercially available turbidimetric assay. With appropriately diluted samples, the range of measurement is 40 to 1000 mg/L. Normal values for women and men were 286 (SD 84) and 340 (SD 55) mg/L, respectively, in good agreement with values published by others.
Subject(s)
Fibronectins/blood , Animals , Antigen-Antibody Complex/analysis , Humans , Immunologic Techniques , Nephelometry and Turbidimetry , Rabbits , Sepsis/bloodABSTRACT
The manual method of Persijn & Van der Slik (J. Clin. Chem. Clin. Biochem. 6, 441-446 (1968): 7, 493-497 (1969); 8, 398-402 (1970) for the determination of serum 5'-nucleotidase has been adapted to the Auto-Analyzer II System. In the Auto-Analyzer II, the incubation temperature for the enzyme reactions is 37 degrees C, and the effective sample speed is 30/h, at a sample/wash ratio of 2:1. There is good agreement and correlation between the manual method and the Auto-Analyzer II method (equation of regression line: y = x + 0.6, correlation coefficient = 0.988; the normal range is 2.9-10.5 U/l for both methods). In routine use, within-run and between-day reproducibility are considerably smaller for the Auto-Analyzer II than for the manual method, especially when large numbers of samples are assayed.
Subject(s)
Nucleotidases/blood , 5'-Nucleotidase , Adenosine Deaminase , Autoanalysis/instrumentation , Autoanalysis/methods , Humans , KineticsABSTRACT
The intermethod analytical variability of 59 commercially available control sera was compared with that of patient sera. For this purpose, patient and control sera were assayed with respect to ten constituents (albumin, alkaline phosphatase, alpha-amylase, cholesterol, glucose, iron, lactate dehydrogenase, creatinine, protein, and urea), each with two analytical methods. Only 6 of the 59 control materials showed an intermethod analytical variability comparable to that of the patient sera for all of the determinations. The use of patient sera for the calibration of routine analytical methods is recommended.
