CH391L/S12/In vitro Selection Overview of in vitro selection In
vitro selection refers to the pursuit of a biopolymer (protein
or nucleic acid) with a new, desired function. Whether beginning
from scratch, or starting with an existing sequence, the first
step is to create a diverse library of variants, each with a
different "fitness" (with respect to the desired function). The
next step to enrich the library for variants with a higher
fitness, thus increasing the overall fitness of the pool. Often
the most difficult facet of a selection is the confinement of
function such that a fit variant increases its own
representation, without non-specifically helping its neighbors.
The last step of a "round" of selection is the amplification of
the recovered product and the regeneration of starting material.
This allows for further cycles of enrichment and increased
fitness. After several rounds of selection, individual variants
are assayed for the desired functionality. In order for in vitro
selection to occur, there m