Step 2 : Gene Cloning
Selecting gene for cloning. (Image by P. Hain)
The second step of the genetic engineering process is gene cloning. During DNA extraction, all of the DNA from the organism is extracted at once. This means the sample of DNA extracted from the Bacillus thuringiensis bacteria will contain the gene for the Bt protein, but also all of the other bacterium's genes. Scientists use gene cloning to separate the single gene of interest from the rest of the genes extracted.
The next stages of genetic engineering will involve further study and experimentation with this gene. In order to do that, a scientist needs to have thousands of exact copies of it. This copying is also done during the gene cloning step.