Hybridization of amplified DNA with the digoxigenin-labeled 24-bp specific probe for P. carinii f. sp. muris (IPL-M) (top) and P. carinii f. sp. hominis (IPL-H) (bottom), defined in the mitochondrial gene encoding the large subunit rRNA. Lanes 1 to 3, control SCID mice (group 8); lanes 4 to 9, mice inoculated with P. carinii f. sp. hominis; lane 10, PCR negative control (with no added DNA); lane 11, DNA ladder; lanes 12 and 13, mice inoculated with P. carinii f. sp. muris; lane 14, P. carinii f. sp. muris organisms used as inoculum for mice from groups 6 and 7; lane 15, positive DNA control of P. carinii f. sp. hominis. The arrow indicates the size (350 bp) of the specific amplified product.