Optimal techniques, situation specific

This maximizes Se (Se l). However, specificity will be minimized as most of the inactive molecules will be in the selection. The situation is reversed in the case where n is very small (n 0). Consequently, one cannot optimize both Se and Sp at the same time and a trade-off is to be determined. If one can choose to rely on one of the above metrics to find an optimum, we have recently advocated the use of a simpler graphical technique which has been adopted as a gold standard in many other research areas the receiver operating characteristic (ROC) curve method [53]. 

Traditionally, the specificity of proteases is determined using standard or optimized peptide libraries containing small recognition sites or, for de novo screening, phage display libraries (Richardson, 2002). These techniques may prove to be useful as a first screening approach. However, they are insufficient to predict the outcome of inhibiting a proteolytic activity in an in vivo situation. 

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