Five patients showing the mixed staining pattern (p., 7, K, and A) were
studied after removal of S.Ig by trypsin treatment and an incubation in a
culture medium for 6-7 hr. Only p. and K determinants were then detected.
In three of these five patients, several experiments showed that this newly
synthetized 1gM was able to spedfically bind normal human IgG.23 These
experiments were conducted with IgG preparations devoid of any aggregated
material since we have found that aggregated normal IgG is able to bind
to all normal or leukemic S.Ig bearing lymphocytes.23 Combinations of antibody
induced redistribution and double labeling experiments performed with
freshly drawn cells indicated that the binding of normal IgG to the S.IgM