Direct Selection and Clone Identification Cloning Strategies

Two Strategies

There are two strategies for obtaining the clone you want.

Ilustration of the problem of selection

Although there are many different procedures by which the desired clone can be obtained, all are variations of two basic themes.

Direct Selection for the desired gene, which means that the cloning experiment is designed in such a way that the only clones that are obtained are clones of the required genes. Almost invariably, selection occurs at the plating out stage.
Identification of the clone from a gene library, which entails an initial 'shotgun' cloning experiment, to produce a clone library representing all or most of the genes present in the cell, followed by analysis of the individual clones to identify the correct one.

In general terms, Direct Selection is the preferred method, as it is quick and usually unambiguous. However, it is not applicable to all genes.

Techniques for clone identification are therefore very important, especially as complete genomic libraries of many organisms are now available.

This guide will explain on how to perform the cloning using the Direct Selection method.