Table 1.

 Cell yield and viability of magnetically isolated and cultured primitive progenitor cells from fetal livers in the first trimester

Embryonic age of FL (weeks)	Total No of cells isolated (×106)	No of CD117+/CD34+/Lin−cells obtained (×104)	Viability (%)	No of cell subpassages obtained	Approximate No of cells obtained at indicated passage
6	6	3.1	93	4	∼5×105
6	5.6	2	95	4	∼4.5×105
6.5	10	4.5	94	2	∼8×105
6.5	6.8	2.5	97	2	∼10×105
8	8	3.2	92	2	∼7×104
8.5	15	6.5	90	12	∼550×106
8	7	3.2	95	12	∼400×106
8.5	18	6.5	92	10	∼70×106
9.5	13	5.5	97	9*	∼50×106
9	11	7.5	94	12*	∼307×106
9	5.6	4.5	93	12	∼360×106
9.5	10.5	7.5	92	12*	∼320×106
9.5	17.6	8.8	95	12*	∼360×106
9	14	13.3	96	11	∼272×106
9.5	15.5	9.5	97	14*	∼389×106
9.5	13.6	12	91	11	∼245×106

*Cells still in culture at present.

FL, fetal liver.