This chapter provides detail description of genetics based analysis in medical laboratory techniques. Chapter has 7 well illustrated diagrams and pictures. Human DNA, cytogenetic methods, harvesting of chromosomes, eye karyotyping, molecular cytogenetic, DNA based methods, genetic linkage, quantification of gene expression and sterilization procedures are described in detail with the help of excellent illustrations. 1 to 2 references are given at the end of each topic for further reading. 13 tables are included to highlight standard protocols of different techniques and sterilization methods.