Possible application of RIA-TEST-T4 (URVJT-Kosice) in congenital hypothyroidism screening

Using a kit for serum thyroxine level estimation (RIA-TEST-T4) commercially made by the Kosice Institute of Radioecology and Applied Nuclear Techniques, the authors modified a version for thyroxine level determination in dry blood drops. Within the 30 to 60 ng.ml-1 range, i.e.; well within the region necessary for congenital hypothyroidism screening, sensitivity proved to be 36 imp.s-1.ng-1.ml. Accuracy at 20 ng.ml-1 was 13%, at 50 ng.ml-1 - 8%, and at 70 ng.ml-1 - 7.6%. Compared with imported kits the cost of examination of one neonate was relatively low. The method lends itself well to mechanization, and screening evaluation time can be reduced to a few minutes. (author)