HemoTypeSC test that uses competitive lateral flow for point-of-care detection of hemoglobin S and hemoglobin C

(A) Design of the HemoTypeSC competitive lateral flow immunoassay. The top panel shows a schematic of the lateral flow test strip with a sample containing Hb S (small yellow circles) and colloidal gold particles (large red circles) conjugated to Hb A (small black squares), Hb S (small black circles), an analog of hemoglobin C (BSA-C; small black triangles), and an irrelevant mouse immunoglobulin (small black stars). The test strip is embedded with monoclonal antibodies (mAbs) directed against Hb C, Hb S, Hb A, and a control. Flow of the sample from the bottom upwards results in capture of the gold particles in positions not blocked by the patient's hemoglobin. Thus, if the patient has Hb S, the binding to the Hb S mAb will be blocked and a line at Hb S will be absent.
(B) Appearance of test strip results for Hb SS phenotype. Note the band at "S" is absent.
(C) Schematic of appearance of test results for each relevant phenotype (AA = normal adult hemoglobin; AS = sickle cell trait; AC = hemoglobin C trait; SS = sickle cell disease; SC = hemoglobin SC disease; CC = hemoglobin C disease).