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retracted or severed axons on the surfaces of the cells.
Therefore, the most accurate count of NF-M(+) cells was
obtained with the day 7 and 8 cells described in the
previous chapter. Even this data may be an underestimate of
the number of NF-M(+) cells for the above reasons.
Polyclonal antibodies specific for the definitive
glial marker GS reacted with approximately 40% of
dissociated day 12 and 13 cells. These cells were A2B5(-)
and so the purified population of A2B5(-) cells (see
analysis of purification below) was approximately 80% GS(+)
(Figs.3-1,3-2). Thus, the astrocytes that were identifiable
as such by immunoreactivity with anti-GS were concentrated
in the purified population.
Dissociated cells at this time also were reactive with
a monoclonal antibody specific for the oligodendrocyte
marker galactocerebroside (GC; Ranscht et al., 1982).
Approximately 6% of dissociated cells were GC(+). Similar
to the analysis of GS, all of these cells were A2B5(-) and
so the purified A2B5(-) cells were 12% GC(+) (Figs.3-1,3-
2). Taken with the results for GS, >90% of the purified
cells could be identified as glia by these two
differentiation markers. A small population of the purified
cells (~4%) could be identified as neurons that contained
neurofilaments.