A radioimmunoassay is described for measuring on a weight basis the total amount of humoral antibodies to the purified protein nerve growth factor (NGF). The technique is based on the primary interaction of the antibodies with 125I-labelled NGF added in large molar excess. The resultant immune complexes are precipitated by ammonium sulfate at 37% saturation, while unbound 125I-labelled NGF is removed with the supernatant. The assay permits measurement of antibodies in a range of sensitivity of 0.1-1.0 ng antibody protein per ml. It is specific and reproducible and permits estimates of the antibody avidity.
ASJC Scopus subject areas
- Immunology and Allergy