Fig. 3.

Composition of proliferating cells after 6–7 days of in vitro stimulation with different kinds of mycobacterial antigen preparations or 3 days of stimulation with phytohaemagglutinin (PHA). TBe, SN1, SN2 and SN3 were prepared as depicted in Fig. 1 and used at a concentration of 9 μg/ml. Bacille Calmette–Guérin-short-term culture filtrate (STCF-BCG), purified protein derivative (PPD) and PHA were used at a concentration of 5 μg/ml. n, Number of donors tested for each antigen preparation; BdU, bromodeoxyuridine.