The simplest service we offer is the counting of comets on slides already prepared by the customer. Our laboratory is equipped with manual and automated image analysis systems and depending on comet number and appearance we choose the optimal scoring method. “Difficult” comets, i.e. those not amenable to scoring with computer imaging software, will be scored visually.
Comet analysis on cells provided by customer
We can carry out a full comet assay analysis on cells provided by the customer, measuring DNA strand breaks and Fpg-sensitive sites (oxidised purines). If required, we can limit measurement to strand breaks, or extend it to measure sites sensitive to other enzymes, such as AlkD (alkylated bases), Endo III (oxidized pyrimidines), T4 endonuclease V (UV damage), or hOGG1 (more specific than Fpg).
Testing chemicals for DNA damage
We treat standard cell lines such as TK-6 lymphoblastoid cells with the chemical provided, over a range of concentrations, with or without S9 activation. Cells are then analysed for strand breaks and (if required) altered bases.