Put E. coli BL21(DE3) into LB medium containing ampicillin and make them propagate until A600=0.6, then add inducer IPTG to induce hRI express.

• 将BL21(DE3)置于含有氨苄青霉素的LB培养基中扩增至A600=0.；6后加入诱导剂IPTG；诱导hRI的表达。