BlueScreen™ HC

BlueScreen Cells

Assay Principles

GADD45a mediates the adaptive response to genotoxic stress. The patented GLuc reporter includes complex regulatory elements, and gives positive results for direct acting mutagens, clastogens, as well as aneugens, and topoisomerase and polymerase inhibitors. Importantly the assay gives correct negative results for non-genotoxins, many of which give misleading positive results in other in vitro tests.

Assay Protocol

Without metabolic activation (–S9)

Eight, 2-fold dilutions of each compound together with positive controls are set out in the 96well microplate and growing cells are added to each well. After incubation for 48 hours and measurement of the flash luminescence in a microplate reader equipped with an auto-injection facility, simple software gives automated decisions and a clear graphical output.

 With metabolic activation (+S9)

Cells are incubated in 96 well microplates for 3 hours in the presence of the test compound and 1% S9 mix. After plate washing to remove S9, the cells are re-suspended in fresh recovery medium for 45 hours.  Following data collection, a data processing template generates positive / negative genotoxicity decisions alongside a clear graphical output.

 Validation

A unique combination of both high specificity and high sensitivity genotoxicity assessment in a human cell line has been demonstrated in a wide range of validation exercises with diverse sets of compounds.  See the literature section (below, right) for details of specific publications.

Automation

The BlueScreen Assay has recently been adapted for automation compatibility and hence use in 384-well format.

BlueScreen-384 publication by GSK