Venema, G. (Hammersmith Hospital, London, England), R. H. Pritchard, and T. Venema-Schröder. Properties of newly introduced transforming deoxyribonucleic acid in Bacillus subtilis. J. Bacteriol. 90:343–346. 1965.—In these experiments, deoxyribonucleic acid (DNA) with donor markers, re-extracted shortly after uptake by competent Bacillus subtilis cells, had abnormal physical properties as compared with DNA with resident markers. It was less sensitive to thermal denaturation, and its capacity to renaturation was reduced. DNA showing joint activity of donor and recipient markers (recombinant-type activity) had similar abnormal properties, revealing that, despite the appearance of recombinant-type activity, integration was not complete.