Radioimmunoassay technology in mass drug screening: an evaluation of an absorbent paper disk transport system

These studies have demonstrated the feasibility of using urine-saturated paper disks in place of urine in the RIA system for drug abuse detection. Results with the disks are consistent with those using urine. A satisfactory procedure has been devised which provides reproducibility of results with no loss of sensitivity or specificity. Further, the procedure is essentially the same as the current procedure requiring urine except that a paper disk punched from a filter paper strip impregnated with urine is used. Complete flexibility is retained to switch from urine to disk. No new or additional equipment is required. It is envisioned that the urine would remain at the collection site and dried filter paper strips containing urine under test be shipped to toxicology laboratories. Sould the disk assay be positive, the urine specimen identified with that disk could then be shipped to the laboratory for confirmation by gas-liquid chromatography or other acceptable methods. The time and expense incurred in shipping large volumes of urine would thus be eliminated.