TABLE 1.

Summary of experiments and cattle groups

Experimental variable	Animal group(s)	Antigen(s) in IFN-γ assay (concn [μg/ml])	No. of cattle	Location	Cattle breed(s)	Age
Effect of blood storage duration on:
Stimulation control	Cattle naturally infected with M. bovis	SEB (1)	34	VLA	Holstein-Friesian	>12 mo
	Cattle naturally infected with M. bovis	PWM (5)	198	Mexico	Holstein-Friesian	>12 mo
Sensitivity and specificity	Cattle naturally infected with M. bovis	Weybridge PPDs	107	VLA	Holstein-Friesian	>12 mo
	Uninfected cattle	Weybridge PPDs	146	VLA	Holstein-Friesian	>12 mo
Sensitivity and specificity with regard to skin test result	Cattle naturally infected with M. bovis	Weybridge PPDs	107 or 324	VLA	Holstein-Friesian	>12 mo
	Uninfected cattle	Weybridge PPDs	874	VLA	Holstein-Friesian	>12 mo
Effect of vessel geometry	Cattle experimentally infected with M. bovis	E:C and PWM (5)	5	NADC	Holstein-Friesian	6 mo (at time of infection)
	Cattle naturally or experimentally infected with M. bovis and uninfected controls	Weybridge PPDs and SEB (1)	23	VLA	Holstein-Friesian	>12 mo
Effect of culture temp	Cattle experimentally infected with M. bovis	Prionics PPDs, E:C, and PWM (5)	5	NADC	Holstein-Friesian	6 mo (at time of infection)
Effect of carbon dioxide	Uninfected cattle	SEB (1 and 0.1)	20	Prionics	Holstein-Friesian and Swiss Brown	2-9 yr
Stability of natural IFN-γ	Uninfected cattle	SEB (1, 0.1, and 0.01)	5	Prionics	Holstein-Friesian and Swiss Brown	2-9 yr
Effect of animal holding conditions	TB-positive herd	PWM (4)	7,988	Northern Ireland	Holstein-Friesian	>6 mo
	Cattle at abattoir	PWM (4)	513	Northern Ireland	Holstein-Friesian	>6 mo
	Uninfected cattle	PWM (5)	317	France	Camargue and Brava	>24 mo
	Cattle naturally infected with M. bovis	PWM (5)	100	Mexico	Holstein-Friesian	>12 mo