Explain how to use genomic and cDNA libraries to find

clones of three human gene homologues of the RAS/MYC/RB oncogenes.

Oncogenes are partially mutated from of proto-onco genes leads to malfunction of their protein products. These onco genes can be identified by preparing the cDNA library of human genome.

Step-by-step explanation

There are more than one way to identify the gene homologues of the RAS/MYC/RB oncogenes in cDNA library of human genome. 

Firstly one can perform hybridization method to identify those homologous genes. The complementary radiolabeled probe is created with respect to those homologous genes which can bind with gene of our interest and subsequently detected by by autoradiography using those DNA print on X-ray plate.

Secondly one can perform colony pcr to screen the gene of interest. In this method gene specific primers are used for pcr reaction. If there any of our gene of interest is present then the polymerization reaction will occur and this particular pcr product can be seen by gel electrophoresis, by which one can conclude that the gene of interest is present or not.

Except those by sequencing those homologous gene present in cDNA library one can compare the mutation between the oncogene and the wild type gene. The screening of product of cDNA library is also can be done by western blotting.