Fig. (2) Ethidium bromide stained 2% agarose gel with amplification products from a case of subretinal abscess suspected to be tuberculous. Lane 1: Reagent control of the first round. Lane 2: Reagent control of the second round. Lane 3: Aqueous humor - negative, Lane 4: FNAB specimen - positive, Lane 5: Blood - positive. Lane 6: Positive control M. tuberculosis (H37Rv). Lane 7: Phi x 174 DNA/Hinf l digest.