This is a question regarding what other proteins might be secreted by or
released from monoclonal antibody producing B-hybridoma cells. We grow a
lot of lines, and after SDS-PAGE analysis, we find non-IgH/non-IgL
proteins in all of them (mostly in the 75-150 kd range). No amount of
disulfide bond reduction or denaturation appears to get rid of them, so I
don't believe them to be unreduced antibody. Also, it doesn't appear to
be strictly related to cell viability, so I don't believe that these are
the result of cellular fragmentation, although there is almost certainly a
contribution by this type of event. I am also not referring to the
proteins contributed by the medium (mostly albumin and transferrin), which
we can identify and distinguish. Does anybody know af anything else that
is secreted in substantial quantities (ca. 5% of the total protein in the
supernatant for each of 4-5 major bands) by B cell hybridomas? Maybe it's
obvious, but it's something I didn't really expect. Thanks for your
input. e-mail: h-petrie at ski.mskcc.org
