title: Radioimmunoassay of rat acute-phase alpha 2-macroglobulin.
abstract: A double-antibody radioimmunoassay (RIA) to acute-phase alpha 2-macroglobulin was developed for the quantitation of this large macromolecule in physiological fluids. The primary receptor for the RIA was a monospecific antiserum to purified acute-phase alpha 2-macroglobulin which produced a high titre (7.5 . 10(6)) antibody with a strong affinity for rat acute-phase alpha 2-macroglobulin (Ka = 1.24 . 10(11)) as measured by Scatchard analysis. The validity of the assay was confirmed by specificity for rat alpha 2-macroglobulin measured in various physiological fluids as assessed by parallel dose-response curves; and accuracy, measured by the analytical recovery of alpha 2-macroglobulin by the RIA in serum (104 +/- 7%) and buffer (103 +/- 7%), and the correlation (R = 0.999) of measurements of acute-phase alpha 2-macroglobulin-containing samples measured in serum and buffer. Reference acute-phase serum measured by this RIA and by rocket immunoelectrophoresis were 98.6% in agreement. Radioimmunoassay sensitivity was estimated at less than 1.0 ng alpha 2-macroglobulin/ml, measured over a range of 0-160 ng. Precision was assessed by intraassay (2.99 +/- 0.97%) and interassay (8.76 +/- 2.64%) variation. Evaluation confirmed that quantitation of rat acute-phase alpha 2-macroglobulin by this RIA met the criteria of sensitivity, validity and precision.
mesh_terms: D000818:Animals; D000915:Antibody Affinity; D005260:Female; D005312:Fetal Blood / Q000032:analysis; D006041:Goats / Q000276:immunology; D007122:Immunoelectrophoresis; D007457:Iodine Radioisotopes; D007700:Kinetics; D011247:Pregnancy; D011863:Radioimmunoassay / Q000592:standards; D051381:Rats; D000511:alpha-Macroglobulins / Q000032:analysis* / Q000276:immunology
chemical_list: D007457:Iodine Radioisotopes; D000511:alpha-Macroglobulins