The document discusses two medical diagnostic techniques: ELISA and PCR. ELISA involves 5 steps - coating a plate with HIV antigens, adding patient serum containing antibodies, adding secondary antibodies linked to enzymes, washing away unbound antibodies, and detecting bound antibodies using a chromogenic substrate. PCR involves sampling, converting RNA to DNA, denaturing DNA, annealing primers, and amplifying DNA through multiple cycles, with the final result seen in a gel. Both techniques are used to detect pathogens like HIV.