Table 2.

Expansion of human MSCs in culture^*

Sample/Passage‡	Observed values for MSCs per 530 cells plated	Calculated cumulative totals†
		MSCs	CFUs
Donor 58R
First	8.0  × 104	7.0  × 107	2.2  × 107
Second	1.1  × 106	1.5  × 1010	0.95  × 1010
Third	2.3  × 105	6.5  × 1013	1.40  × 1013
Donor 58L
First	8.6  × 104	1.1  × 108	0.25  × 108
Second	4.2  × 105	1.1  × 1010	4.1  × 1010
Third	3.1  × 105	5.0  × 1013	1.5  × 1013
Donor 59R
First	1.9  × 105	2.8  × 108	1.1  × 108
Second	2.4  × 105	1.3  × 1011	5.5  × 1010
Third	7.5  × 105	1.8  × 1014	5.2  × 1013
Donor 59L
First	1.4  × 105	2.4  × 108	0.91  × 108
Second	1.7  × 105	7.8  × 1010	3.7  × 1010
Third	5.0  × 105	7.4  × 1013	2.2  × 1013

^*For each passage, 530 MSCs were plated in 176-cm² plates for an average plating density of 3.0 cells/cm². The cultures were incubated for 14 days, harvested with EDTA/trypsin, and an aliquot of 530 cells replated at a density of 3.0 cells/cm². 

^† Calculated cumulative total of MSCs and CFUs if all the MSCs from the frozen stock and each passage had been replated at 3.0 cells/cm². 

^‡ The samples were from bone marrow aspirates obtained at the same time from two normal volunteers (58 and 59), one from the right iliac crest (58R and 59R) and one from the left iliac crest (58L and 59L). Each of the aspirates was about 20 ml, from which 1.2 to 2.7 × 10⁷ nucleated cells were obtained. The nucleated cells were plated at high density to obtain frozen stocks of early passage MSCs (see text).