Cell lysis can be achieved through physical or chemical disruption; both were utilized in the experiment through homogenization of the liver and utilization of sodium dodecyl sulphate (SDS) solution. Lysis is usually carried out in a salt solution to aggregate protein and cellular debris, saline-ethylenediaminetetraacetic acid (EDTA) was utilized in the experiment. EDTA is a chelating agent that binds to magnesium and calcium ions that are necessary in the action of DNase (World of Forensic Science 2006). The solution usually contains a detergent, in this case SDS, which disrupts the cell membrane through the denaturation of proteins (University of Utah 2011). Heat can promote lysis of cells though subsequent cooling is essential to ensure integrity of the DNA.
DNA purification can be achieved through the use of chemicals, particularly: phenol, chloroform and isoamyl alcohol. Phenol disassociates proteins from DNA; the nonpolar solution causes a change in the polarity of proteins. The less-polar residues of the amino acids (usually surrounded by polar residues in vivo) fold out making it soluble in the nonpolar phenol (Oswald 2008). Chloroform denatures proteins and lipids and it also makes DNA less soluble to phenol; it is usually mixed with isoamyl alcohol to prevent reaction with oxygen. Isoamyl alcohol also reduces foaming (Moors 2011).