DNA Damage Assay Human bronchial epithelial cells (hBE)

A key signature for necrotic cells is the permeabilization of the plasma membrane. Necrosis can be quantified by several cellular and biochemical assays. When studied minutely, it reveals the difficulty in confirmation in secondary induction of necrosis in apoptotic cells. Apoptotic cells are being analyzed to shift to necrotic status owing to membrane permeability at later stages, and thus, discrimination of two cell death becomes critical. Therefore, it is crucial to use a necrosis detection kit or a defined procedure to analyze this unprogrammed form of death in response to immense chemical and physical insults.

Plasmid isolation is an important technique in molecular biology or any kind of genetic editing. It involves amplifying plasmids overnight by transforming them into competent bacterial cells. The desired colonies of these bacteria can then be grown in shaker cultures, at appropriate shaking speed, oxygen availability and temperature. These liquid cultures can then be ultracentrifuged to pellet the bacteria, which are then used for plasmid isolation. The bacteria are first resuspended in a buffer, then lysed, neutralized, purified in a column, eluted, precipitated with ethanol and then resuspended. During plasmid isolation, it is important to lyse cells quickly because lysing bacteria for too long may lead to irreversible denaturing of the plasmid. Usually, alkaline lysis is used for isolation because it is a mild treatment. It isolates plasmid DNA and other cell components such as proteins by breaking cells apart with an alkaline solution. Precipitation removes the proteins, and the plasmid DNA recovers with alcohol precipitation. Resuspension and lysis buffers should be mixed thoroughly in order to prevent the DNA from breaking into smaller fragments. This is because broken gDNA can reanneal and remain in the solution, without binding to the column.