Contamination of Anti‐Immunoglobulin Reagents with Antibodies to β‐Microglobulin and Other Unrelated Antigens

Publisher Website
Google Scholar
Abstract
IgG fractions from three of four rabbit antisera to Bence Jones proteins of x‐type were found to contain antibodies to β2‐microglobulin and to stain 80%–100% of human blood lymphocytes by indirect immunofluorescence. Antibody fractions from these sera, which contained anti‐β2‐microglobulin but not anti‐Ig, stained all lymphocytes, whereas the isolated anti‐Ig antibodies (anti‐x) stained only a minor cell population. In both instances, the specificity of the staining was confirmed by absorption experiments. One antiserum to the constant half of λ ‐type Bence Jones protein also contained antibodies to β2microglobulin and stained all lymphocytes. Four other anti‐λ reagents contained no antibodies to β2‐microglobulin and stained at most about half of the lymphocytes. The antigen responsible for this staining is unknown. The isolated anti‐immunoglobulin antibodies (anti‐λ) stained only 5%–10% of the lymphocytes. Antisera to serum IgG or its fragments were free of antibodies to β2‐microglobulin and stained only 10%–23% of the lymphocytes. This staining was in all instances due to Antibodies to human immunoglobulin. Five of eight undiluted sera from normal rabbits with no detectable antibodies to human immunoglobulin or β2‐ microglobulin stained 25%–60% of the lymphocytes. This staining rapidly disappeared on dilution.