Overall levels of scFv expression exhibit strong positive correlation with phage display propensity. Average relative rankings obtained for overall scFv expression in the spheroplast fraction of E. coli are displayed on a scatter-plot in relation to average relative phage display propensity rankings for each individual clone. A ranking of 1 represents a high relative level of overall expression or phage display propensity and a ranking of 15 represent a low relative level of overall expression or phage display propensity. The plot shows a strong positive correlation between expression ranking and display level ranking. Each scFv x-axis co-ordinate represents the average ranking from 3 independent experimental observations of overall scFv expression (Table 1). Each scFv y-axis co-ordinate represents the average ranking from 6 independent experimental observations of display level (three ELISA and three western blots) carried out on three batches of phage-scFv (Table 1). The Spearmans coefficient of rank correlation Rho coefficient for this association is 0.88 representing strong positive correlation with a p-value < 0.005. Standard errors are not conventionally used for averages of ranks. However they have been calculated (Table 1) and are not shown graphically for purposes of clarity.