At the present level of the biotechnology what are the main techniques of genetic engineering?

The main methods of genetic engineering today are: the recombinant DNA technology (also known as genetic engineering itself) in which pieces of genes from an organism are inserted into the genetic material of another organism producing recombinant beings; the nucleus transplantation technology, popularly called as "cloning", in which a nucleus of a cell is grafted into a enucleated egg cell of the same species to make a genetic copy of the donor (of the nucleus) individual; the technology of DNA amplification, or PCR (polymerase chain reaction), that permits millions replications of chosen fragments of a DNA molecule.

The recombinant DNA technology is used to make transgenic organisms, like mutant insulin-producing bacteria. The nucleus transplantation technology is in its initial development but it is the basis, for instance, of the creation of "Dolly" the sheep. PCR has numerous practical uses, as in medical tests to detect microorganisms present in blood and tissues, DNA fingerprint and obtainment of DNA samples for research.