Abstract: This paper describes a m(?)dified (?)ieimmunoassay for minute albuminuria using a solid phase radioiodination technique(Iodogen), and a precipitating reagent(PR) separation. The results of RIA and EIA of albumin are compared with each other(r= 0. 925). Aliquots of 100μl diluted urine(1: 20—1: 100) are incubated at 4℃ overnight with 100μl ~(125)I-Iabelled albumin and 100μl antiserum. Separation with 500 μl PR is very successful. The concentration of standard albumin ranges from 50 to 3200 ng/ml. The sensitivity of detection is 5 ng of albumin. The coefficients of inter-assay and intrar-assay variation are 3. 2—8.2% and 13.0—14.5% respectively. In 70 normal individuals the range of urinary albumin is 1. 2—17. 8mg/24h.