Product category:
Assay kits
News Release from: Guava Technologies | Subject: ViaCount
Edited by the Laboratorytalk Editorial
Team on 26 June 2003
Early detection of cell health
New assay means biologists can get a more complete assessment of the health of living cells than is possible using the standard approach of Trypan Blue-based dye exclusion
Guava Technologies says that life science researchers can accelerate their research by detecting cell health earlier using its ViaCount assay Using Guava's proprietary ViaCount assay, biologists can now get a more complete assessment of the health of living cells employed in research and biopharmaceutical production than is possible using the standard approach of Trypan Blue-based dye exclusion
This article was originally published on Laboratorytalk on 20 Jun 2007 at 8.00am (UK)
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Guava Technologies claims the ViaCount assay is revolutionising the way cell counting and viability assessment are done in life science laboratories around the world
By enabling biologists to accurately detect and quantify apoptotic cells simultaneously with their analysis of cell viability, ViaCount enables users to detect problems in cell cultures much earlier, saving time and money.
Trypan Blue exclusion is the most widely accepted and widely used method for enumerating living and dead cells in culture.
Individual cells within a single culture may vary substantially in the amount of dye absorbed, making interpretation of results subjective, even when researchers use newer automated methods of assessing cell viability by Trypan Blue staining.
Further reading
Counting and assessment of difficult cell types
Assay results using this system are said to be more reproducible, with less operator-to-operator variability in results, and with rapid data acquisition to save researchers significant amounts of time
Counting white cells in unlysed whole human blood
Application note describes use of assay system which overcomes limitations of manual counting by staining and counting only the nucleated white blood cells
Moreover, several published research studies have demonstrated that Trypan Blue methods, both manual and automated, consistently over-estimate the number of viable cells in a cell population.
"Since we've acquired the Guava PCA, we no longer use hemacytometers to perform viable cell counts", said Jennie Mather, CEO and president, Raven Technologies.
"Furthermore, the Guava PCA system is a major advance in our ability to rapidly and easily measure most of the parameters important in cell biology." Rather than looking at the generalised staining of cells based solely on membrane integrity, Guava ViaCount employs a combination of dyes that specifically bind to DNA.
The first of these dyes penetrates membranes, entering and staining the DNA of all nucleated cells.
The second is a viability dye that penetrates and stains DNA in dead and dying cells with compromised membrane integrity, and is excluded by cells with intact membranes.
Cells that take up intermediate amounts of the viability dye also react with Annexin V, indicating they have entered the apoptotic pathway leading to cell death.
Moreover, dye that is not bound to DNA does not produce a fluorescent signal, further improving resolution of the ViaCount assay.
Guava Technologies is offering researchers a new technical paper on Guava ViaCount and its advantages over Trypan Blue-exclusion staining entitled, 'A better alternative to traditional methods for cell counting and viability assessments - new platform for a broad range of cell-based assays.' Copies of this article can be accessed from the Guava Technologies website.
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