Fig. 2

Diagram of simple immunostick test for the screening of SEA type deletion α-thalassemia 1. (A) Pre-coated immunostick containing 4 paddles was prepared as Fig. 1a (test paddle: mAb PL2; positive control paddle: goat anti-mouse immunoglobulins antibody; isotype-matched mAb control paddle: mouse IgG1 mAb; and negative control paddle: left as uncoated). (B) For the first step, immersion of the pre-coated immunostick into cocktail containing tested hemolysate, detecting mAb (biotinylated-mAb PL3; PL3-biotin), and HRP-conjugated streptavidin (streptavidin-HRP) at 37 °C for 1 h. (C) For second step, the immunostick was dipped into precipitating TMB substrate. (D) The positive reaction (presence of ζ-globin chain) was seen as a blue color spot on the stick paddle. A brief washing between first step and second step was done by dipping stick in 0.05% Tween-PBS and agitating for 5 s