Effect of rare tRNA supplementation on HIV-1 CA expression in NiCo21(DE3) E. coli.Rare codon analysis of open reading frame (ORF) coding for HIV-1 p24 gene (A). NiCo21(DE3) E. coli were transformed with pACYC-RIL or pRARE2 or pRARE2-lysS and subsequently transformed with pSA-Hp24-6His vectors and selected on LB + Cam + Amp plates. Cultures were grown in presence of Cam + Amp at 22°C for 12 hours, either induced with 0.05 mM IPTG, or un-induced. Cultures were processed to obtain whole cell lysate (WCL), insoluble (S), and soluble (S) fractions. Samples were electrophoresed on 12% gel, stained with Coomassie Blue G250, and photographed (B). Lane M, BenchMark Pre-stained protein ladder; Lanes WCL, whole cell lysate; Lanes IS, insoluble fraction; Lanes S, soluble fraction.