Less LDH in any transfected group indicates that the cell proliferation was inhibited.In a normal culture condition (control group), LDH can also be released by cells into medium. This can be evidenced by comparing the OD value of 'control' group with that of 'only medium' group. Under untoxic condition (no cell death), the OD value is theoretically proportional to the number of cells.

High LDH in any specific line indicates increased damage to plasma membrane and cell cytotoxicity .....

LDH assay measures activity of the cytoplasmic LDH enzyme in the media. During cytotoxicity due to the loss of the membrane integrity its activity increases in media. A classical approach to interpret it would be to investigate the ratio of the activity observed in the sample (treated cells) to control (nontreated cells). A comprehensive formula should also include negative control (water or PBS) and will look like this: cytotoxicity (%) = [treated - negative control] / [nontreated - negative control] x 100

Ali Burak Özkaya Thank you but how to interpret the degree of cytotoxicity as compared to untreated.