Figure 1
Overexpressed and purified rDer f 21 analyzed using 12% SDS–PAGE followed by Coomassie Blue staining. Lane 1, PageRuler Plus Prestained protein ladder (labelled in kDa; Thermo Scientific, USA). Lane 2, pellet of crude extract before IPTG induction as a negative control. Lanes 3–5, total protein, pellet and supernatant of crude extract after IPTG induction, respectively. Lane 6, purified rDer f 21 protein using Ni–NTA affinity chromatography. |