Table 1.

	Days after immunization	Precursor frequency	Number of LN cells	Total number of SWM-specific Vβ8+ cells
		1/x	z × 106	(z/100)/x
Primary	3	1/3,150	10.23	33
	6	1/38	12.8	3,368
	8	1/65	9.44	1,452
	14	1/362	15.6	431
	28	1/405	8.73	215
Secondary	2	1/217	23.55	1,085
	4	1/37	20.95	5,662
	6	1/42	20.00	4,762
	8	1/76	12.65	1,665
	14	1/125	10.35	828

Determination by LDA of antigen-specific precursor frequencies in the CD4^highVβ8⁺ population. The total number of antigen-specific precursor cells present in the LNs during the primary and secondary response to SWM 110–112 in the Vβ8⁺ population was derived from the precursor frequency of antigen-specific T cells in the CD4^highVβ8⁺ subset and from the total number of LN cells (z), using the equation n = (z/100)/x. CD4^highVβ8⁺ cells were sorted from primed LNs at days 3, 6, 8, 14, and 28 after primary immunization and days 2, 4, 6, 8, and 14 after secondary immunization. LDA was performed and the precursor frequency (1/x) was derived by Poisson statistics as described in Materials and Methods. Shown are the results of one representative LDA experiment performed at each selected time point.