An ELISA employing a Haemophilus influenzae type b oligosaccharide-human serum albumin conjugate correlates with the radioantigen binding assay

J Immunol Methods. 1990 Dec 31;135(1-2):121-8. doi: 10.1016/0022-1759(90)90264-v.


An ELISA measuring total Ig antibodies to the capsular polysaccharide of Haemophilus influenzae type b (HbPs) in human sera using an antigen composed of Haemophilus b oligosaccharides conjugated to human serum albumin (HbO-HA) was shown to have an excellent correlation to the radioantigen binding assay (RABA). When 214 sera with different anti-HbPs levels were assayed for total Ig by HbO-HA ELISA and by RABA the correlation coefficient was 0.917 and the paired t test p value was 0.575. Use of competitive ELISA employing soluble HbPs, HbO-HA and human albumin as competitors, showed that the HbO-HA ELISA was specific for antibodies to HbPs. The HbO-HA ELISA yielded reproducible results both within and between laboratories. The HbO-HA ELISA can also be used to determine the isotype of anti-HbPs antibodies by using isotype specific enzyme conjugates. The sum of the IgG, IgA and IgM HbO-HA ELISA results had excellent correlation to the RABA results (correlation coefficient = 0.976). Thus, the HbO-HA ELISA can be substituted for the classical RABA and also be utilized for quantitating the isotype of the anti-HbPs antibodies.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Antibodies, Bacterial / blood*
  • Antibodies, Bacterial / immunology
  • Antibody Specificity / immunology
  • Bacterial Capsules
  • Bacterial Vaccines / administration & dosage
  • Bacterial Vaccines / immunology*
  • Binding, Competitive / immunology
  • Child
  • Enzyme-Linked Immunosorbent Assay / methods*
  • Haemophilus Vaccines*
  • Haemophilus influenzae / immunology*
  • Humans
  • Immunoglobulin A / analysis
  • Immunoglobulin G / analysis
  • Immunoglobulin Isotypes
  • Immunoglobulin M / analysis
  • Polysaccharides, Bacterial / administration & dosage
  • Polysaccharides, Bacterial / immunology*
  • Radioligand Assay / methods
  • Reproducibility of Results
  • Serum Albumin / immunology*
  • Vaccination


  • Antibodies, Bacterial
  • Bacterial Vaccines
  • Haemophilus Vaccines
  • Haemophilus influenzae type b polysaccharide vaccine
  • Immunoglobulin A
  • Immunoglobulin G
  • Immunoglobulin Isotypes
  • Immunoglobulin M
  • Polysaccharides, Bacterial
  • Serum Albumin