In Vitro Micronucleus Assays Now Available by Flow Cytometry

We are pleased to now offer the Litron in vitro micronucleus (MNvit) assay. This assay, available at our Edinburgh site, offers accelerated turnaround times. In addition, more cells are analyzed which therefore improves the power of the assay. The in vitro micronucleus assay is also available via microscopy at our Montreal facility.
 
We selected TK6 cells for the MNvit (by flow cytometry) as they are human derived (lymphoblastoid) cells and are p53 competent. They are routinely used for genetic toxicology experiments. The cultures are treated in the presence of exogeneous metabolic system (S9) for 6 hours (with 22 hour recovery) or in the absence for 28 hours. The cells are then stained with relevant nucleic acid dyes before analysis by flow cytometry. Flow cytometry gatings are set to exclude necrotic cells. The majority of the cells fall in the “nucleated” quadrant. Cells containing micronuclei appear in the micronucleated (“MN”) quadrant to the left. As can be seen in the plots, the positive control has a higher number of events in the “MN” quadrant when compared to the vehicle control. 

The MNvit assay offers the benefit of objective analysis of ca 50,000 cells per culture for the presence of micronuclei with results available 2 days post-dosing.