Table 1. Average yield and viability of cells following digestion and negative selection of ONE fourth mammary fat pad from a wild-type Charles River Sprague-Dawley female.

Postnatal Age (Days)	Average number of cells digested (x 106)	Average viability after dissociation (%)	Average number of negatively selected cells (x 106)
8 (n = 1)	3.0	72	---
20-30 (n = 20)	16.7	56	4.4 (n = 7)
30-40 (n = 16)	33.0	44	6.6 (n = 3)
> 40 (n = 26)	88	41	2.9 (n = 7)