Western Blot Analysis of Three Recombinant Yeast Colonies; Lane 1 and 3 are the product analysis of X-33 and PichiaPink strain 4 expression systems, respectively. The absence of 50 kDa band implies that the two strains have failed in expressing the recombinant protein. In contrast, the visible 50 kDa band in lane 2, which belongs to PichiaPink strain 2, indicates the successful recombinant protein production by this strain.