Experience a more convenient workflow for your high-throughput cytotoxicity and proliferation screening projects with the CyQUANT™ Direct Cell Proliferation Assay–no washes, cell lysis, temperature equilibrations, or radioactivity required. DNA-based assays have been shown to be among the most sensitive cell health indicators and data concordance with metabolically based assays is excellent. The CyQUANT™ Direct assay is a highly sensitive and robust method to assess cell growth, viability, or compound toxicity in a range of applications, from high throughput screening to bioproduction.

Features of the CyQUANT™ Direct Cell Proliferation Assay include:

• More convenient workflow for high-throughput screening–no washes, cell lysis, temperature equilibrations, or radioactivity required
• Rapid protocol, high sensitivity and dynamic range
• Measures independent of metabolic state of cells on standard fluorescent plate readers
• Multiplex assays using a spectrally distinct fluorescent or a luminescent readout

Rapid and convenient, with a large dynamic range
The CyQUANT™ Direct assay is a fluorescence-based proliferation and cytotoxicity assay for microplate readers with a linear detection range from less than 100 to 20,000 cells per well in most cell types. The no-wash, homogenous format and fast add-mix-read protocol makes the CyQUANT™ Direct assay ideal for HTS applications. The assay can be completed in one hour, with no washes, no cell lysis, or temperature equilibrations required. The signal is stable for several hours, affording additional work flow convenience.

How it works
The CyQUANT™ Direct assay is based on a cell-permeant DNA-binding dye in combination with a masking dye reagent. Cellular DNA is highly regulated and estimates of cell numbers based on DNA are very accurate. The masking dye blocks staining of dead cells or cells with compromised cell membranes resulting in only healthy cells being stained. The CyQUANT™ Direct assay, therefore, measures proliferation as well as membrane integrity, another measure of cell health. Users of metabolically based cell health assays can readily compare historical data with results from the CyQUANT™ Direct assay, as concordance assays based on metabolism or energy (ATP) has been shown to be excellent. Furthermore, it is possible to multiplex with spectrally distinct fluorescent probes or luminescence assay kits because cells are not lysed. Furthermore, the fluorescent signal allows the user to switch between HTS and HCS plate readers if multiplex assays require different platforms.