Because of advances of technologies in the field of genmic epidemiology in the recent years, specimen collection, storage and analysis became an essential part of research methodologies. DNA is now being used in epidemiologic studies to evaluate genetic risk factors and specimens other than the fresh whole blood can De used for PCR. Therefore, All nucleated cells, such as buccal swabs and urine specimens, are suitable for DNA analysis. For an unlimited source of genomic DNA, EBV transformation of lymphocytes can be used for immortalization. However, the type of specimen collected in genomic epidemiologic studies will depend on the study where the epidemiologist play a leading role for the design. We also briefly described various finds of analysis for SNP that is an essential part of the genomic epidemiology.