An Avery family portrait, 1886. Oswald is seated to the left of his father, the Reverend Joseph Francis Avery.
1900 picture of the Colgate band. Avery is seated in the middle holding his cornet.
Oswald Avery at work in the laboratory, around 1930.
Memo approving Avery's appointment to the Rockefeller Institute.
Avery at a 1940 Christmas party.
A page from the May 15, 1943 letter from Oswald Avery to his brother Roy. In the letter Avery speculated on how transformation could happen. Avery never publicly connected genes with DNA and his transformation experiments.
Colin Munro MacLeod, 1936.
Maclyn McCarty, 1936.
Maclyn McCarty in his office at Rockefeller University, 1999.
By all accounts, Avery was a careful, fastidious scientist. He disliked collecting Pneumococcus bacteria and doing the subsequent lysis. It wasn't from fear of infection, but because Avery thought the whole procedure too messy.
Could Avery have proven that DNA is the transforming principle without enzymes like trypsin, chymotrypsin, DNase, or RNase? Can you think of an experiment that would work?