Berson and yellow 1st described the following test: (A) RIA, (B) ELISA, (C) Immuno chromatography, (D) Chemiluminescence assay
Answer is A. Berson and Yalow discovered RIA in 1959 by which we can quantify antigens or hormones upto picograms-v sensitive than ELISA RIA /ELISA-indirect immunofluorescence tests Ref: Textbook of Microbiology Baveja 5th ed Pg 115