“…Since deoxyribonuclease but not ribonuclease or trypsin inacti-vated the preparation, they suggested that DNA determined transplantation specificity. However, Haskova and Hrubeskova, as well as Medawar, were subsequently unable to elicit accelerated rejection with purified DNA (101). Furthermore, Castermans and 0th (102) found that extraction of the homogenate of the nucleus with sodium chloride yielded an active supernatant that did not contain DNA, and an inactive sediment that did contain DNA, thus proving that a component other than DNA carries the antigenic specificity.…”