Radioimmunological detection of morphine in stains of blood and urine.

Morphine in blood and urine spots was detected by the radioimmunoassay (125-J-Abuscreen R, Hoffmann La Roche) in nanogram quantities. Blood and urine drops containing morphine (5 or 20ng) were dropped on wood, fired clay or cotton and stored for perios of 1 to 21 days in a dry or humid environment. Detection in blood stains on cotton was achieved in all cases. Results were more variable in blood spots on clay or wood, but in most cases detection was possible. In urine, morphine was detectable only on cotton. The differences are explained by different degrees of adsorption of blood and urine on the materials and the difficulties of elution thereof.