Figure 1.

Construction and PCR confirmation of the expression vector of EPO after the addition of secretory signal by using overlapping primers. (A) Schematic diagram showing the signal sequence addition using six overlapping primers before the 495 bp of mature EPO. Sequences of primers are given in Table 1. (B) Agarose gel electrophoresis showing step wise addition of secretory signal. M, 100bp DNA ladder; Lane 1-6 sequential addition of secretory signal sequence, after every PCR 15-18 bp of the secretory signal is added. The final 588 bp (including restriction sites) fragment of the EPO fused with 81 bp of signal peptide is achieved.