TABLE 1.

Effects of culture techniques on IFN-γ responses by infected reindeer^a

Stimulant	Mean ΔOD ± SEM for:
	Immediate setup	24-h delayed setup
		Without stimulation	With stimulation
M. avium PPD	0.303 ± 0.049 (n = 56)	0.300 ± 0.040 (n = 56)	0.183 ± 0.029 (n = 30)
M. bovis PPD	1.285 ± 0.105 (n = 56)	1.191 ± 0.089 (n = 56)	1.054 ± 0.112 (n = 30)
rESAT-6-CFP-10	1.291 ± 0.103 (n = 43)	1.268 ± 0.104 (n = 43)	1.072 ± 0.144 (n = 20)
PWM	0.839 ± 0.084 (n = 56)	0.758 ± 0.075 (n = 56)	0.355 ± 0.050b (n = 30)

^aHeparinized blood samples were obtained from M. bovis-infected reindeer at various time points after challenge. Blood was dispensed in 1.5-ml aliquots either immediately or after a 24-h delay at RT into individual wells of a 24-well plate. Treatments included no stimulation (PBS), M. avium PPD (40 μg/ml), M. bovis PPD (40 μg/ml), rESAT-6-CFP-10 (10 μg/ml), and PWM (20 μg/ml). Blood cultures were incubated for 48 h (with either an immediate or a delayed setup), plasma was harvested, and IFN-γ concentrations were determined using an ELISA-based kit. Absorbencies of standards and test samples were read at 450 nm using an ELISA plate reader. Duplicate samples for individual treatments were analyzed.

^bDiffers from PWM responses obtained with an immediate setup and with a delayed setup without stimulation (P < 0.01).