Cell lysis buffers have many purposes. Firstly, it lyses the nuclear membrane in addition to a cell membrane. Secondly, it maintains the pH during the DNA extraction. Thirdly, it protects DNA from acidic degradation. Fourthly, it separates DNA from other cell debris. Fifthly, the lysis buffer helps maintain the integrity of the DNA. These purposes all together make it a very useful buffer when doing DNA extraction experiments.