Figure 1

Different components of a two-band RDT. Blood is applied on the sample pad at the proximal part of the RDT and buffer is dropped on the buffer pad. The absorption pad that consists of filter paper sucks the solution to the distal part of the RDT. Detecting antibodies conjugated with colloid gold are present on the conjugate pad coloring it pink. On the nitrocellulose membrane, test lines with capture antibodies for HRP-2, pLDH or aldolase and a control line with control antibodies are present. Depending on the RDT brand, the sample pad, buffer pad and conjugate pad are either separate or combined in one component. Those three pads consist of fiberglass-like paper strips and partly overlap the nitrocellulose membrane. All components are glued onto a plastic backing. Some RDTs contain a plastic cover on top of the nitrocellulose membrane (not illustrated). Most RDTs are packed in a plastic cassette housing or available as cardboard or hybrid format. The arrow indicates the direction of the lateral flow from proximal to distal RDT components.