Specificity of epitopes. A. Test strips with immobilized 7G9 and 17E4 were reacted with high levels of pLDH from the indicated species (1:10 dilution of stock enzyme to mimic a > 100% parasitaemia). Immunoreactive bands were visualized with 6C9-conjugated colloidal gold. A control (Cont) line comprised of goat anti-mouse antibody is also shown. B. Test strips with 13H1 and 17E4 were reacted with a serial dilution (1:10) of Pf-LDH where the starting concentration represented a > 100% parasitaemia. C. Competition experiment to demonstrate epitope differences and similarities. Prior to wicking up the strip, the Pf-LDH sample was incubated with buffer (ø) or buffer containing excess 17E4, 7G9, 19G7, or 13H1 antibodies as indicated at a final concentration of 200 μg/ml for 2 min. D. A serial dilution (1:10) titration of Pf-LDH was analyzed on test strips with immobilized 7G9 and 17E4. Bands were visualized with 6C9-conjugated colloidal gold. E. Test strips with immobilized 14C2 and 15F10 were reacted with Pf-LDH and 19G7-conjugated colloidal gold. The Pf-LDH samples were preincubated with buffer alone (ø) or free 6C9, 2B5, or 19G7 antibody for 2 min prior to analysis.