The ability of the 5E phage antibody to detect PDI family proteins was tested by Western-blot analysis. Lane 1, marker proteins; lane 2, hPDR; lane 3, hPDI; lane 4, bPDI; lane 5, hP5; lane 6, yPDI. The 5E phage antibody (1011 pfu/ml) and each protein (approx. 5 μg) were used. The asterisk indicates a breakdown product of hPDIR.