Table 2.

Pretransplant transduction efficiency as judged by plating efficiency in methylcellulose supplemented by taxol

Suspension	Stromal
20.1	14.7
18.1	9.4
16.5	8.1
8.4	4.3
6.0	2.7
5.7	2.2
5.7	2.1
2.5	1.0
2.3	1.0
2.0	−0.22
8.7	4.5

A comparison of the transduction frequencies by assaying the plating efficiency of GM-CFU in methylcellulose supplemented by taxol. It is to be noted that this assay also documents expression of the vector GM-CFU in the myeloid progenitor cells, because expression of the vector MDR-1 transgene is necessary for increased plating efficiency. The method of the plating assay is summarized in text.