98
Table 3-1
3H-thymidine incorporation:
Day 12-13 cells
Cells
Score
% Labelled Nuclei
Unpurified
1
11/315
3.5%
2
21/790
2.7%
mean=3.0+0.4
3
9/326
2.8%
Purified
1
33/722
4.6%
2
94/814
11.5%
mean=6.7+3.4
3
15/383
3.9%
 3H-thymidine incorporation into cells during 24 hours in
culture. The results of 3 experiments are shown. In 2 of
the 3 experiments (#1 and 3) both unpurified and purified
cells contained a small percentage (<5%) of labelled
nuclei. In 1 experiment (#2) the purified cells contained
a much higher percentage of labelled nuclei (4x) than did
unpurified cells. In all cases, labelled nuclei were in
A2B5(-) cells. Newly recruited A2B5(+) cells in purified
cultures therefore did not require new DNA synthesis for
this change in phenotype.