Standardization for four protein analytes with the Behring Nephelometer.

Abstract

Owing to the generally higher values observed in the initial establishment of immunoglobulins (Ig) G, A, and M assays with the Behring Nephelometer, we elected to verify five commercial protein calibrators. This initial verification was performed by standardizing the Behring Nephelometer with the World Health Organization (WHO) International Reference Preparation for Human Serum Immunoglobulins G, A, and M. The instrument was also standardized for immunoglobulins and transferrin with use of the Reference Preparation for Serum Proteins (RPSP II). Analytical recoveries of the commercial calibrators varied. Also, assigned protein concentrations in both the WHO and RPSP II preparations made them unacceptable to us as benchmark calibrators for the Behring Nephelometer. Individual proteins (IgG, IgA, IgM, and transferrin) were obtained and primary standards prepared. Both transferrin and IgG were successfully standardized. However, IgA and IgM primary standards lacked 100% antigenicity, requiring removal of nonreactive IgA and IgM or reassignment of the correct value. The problem remains to find appropriate purified materials for IgA and IgM standardization.

Impact of occupational exposure to elemental mercury on some antioxidative enzymes among dental staff

“…Assessment of renal function. Quantitative analyses of proteins in urine were performed using a Behring BN II nephelometer (Schotters et al, 1988). Glomerular renal function was assessed by determining albumin in urine, while tubular renal function was assessed by determining a1 microgloblin in urine.…”