Importance of Template Concentration

This behavior can be rationalized by considering the total template binding energy gained by the system. In the presence of excess template the building blocks are limiting. For example, where a system has a choice between producing two copies of a dimeric library member versus one copy of a tetramer, it may prefer 

The above example makes it clear that the amount of template in the system is an important and easily controllable experimental variable. There is a trade-off 

Note that the equilibrium constants describing the formation of library members from their building blocks is not always chemically realistic. For example, in disulfide chemistry the conversion of thiols into disulfides is an irreversible process. However, treating this process as a fictitious equilibrium is equivalent to going through a series of more chemically realistic exchange steps and mathematically much simpler to deal with. 

In summary, careful design of the building blocks and the experiments, and a crihcal and prepared mind when interpreting the results, are essential before the correct conclusions can be drawn from the often complex response of DCLs to molecular recognition events. 

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