Table 2.

Growth in Semisolid Medium of Cells Expressing the gp140^trk Receptors

Cell Line	Number of Cells	Additionsa	Agar Coloniesb	NGF Stimulation
NIH 3T3	103	–	1
	103	NGF	0	None
	104	–	1
	104	NGF	2	None
E25-48	103	–	12
	103	NGF	111	9-fold
	104	–	79
	104	NGF	546	7-fold
B38-94	103	–	98
	103	NGF	90	None
	104	–	1604
	104	NGF	1356	None

^aCultures were fed every 4 days with 0.5 ml of DMEM containing 5% calf serum in the absence or presence of 30 ng/ml NGF as indicated.

^bColonies containing more than 32 cells were scored as positive after 4 weeks of culture.