The four new assays expand Guava's current selection of assays for assessing cellular function in cancer-related areas of research and will have important applications in other areas in oncology too.
The 96-well microplate analysis format of Guava's EasyCyte benchtop microcytometry system increases the cell-based assays a single researcher must perform, all of differing types in a single day.
"With a single platform, the assays can interrogate multiple functional parameters in the cell in the context of absolute cell counts, subpopulation analyses, and viability," said David Ferrick, Guava's vice president, biology and clinical applications.
"We believe our approach to cell biology can enhance researcher understanding of the underlying biology. Guava has bought the power of cytometry with today's microplate-based workflow," he added.
The new mix-and-read Guava MitoPotential assay measures changes in the ion gradient across the mitochondrial membrane. These gradient changes can indicate early stages of apoptosis, or cell death, and are significant for understanding a number of diseases including multiple cancers, diabetes, and rheumatoid arthritis.
There is growing interest within the scientific community to evaluate changes in the mitochondrial membrane potential and further define its role in initiating apoptosis, cell cycle, and other cellular processes. Automated single-cell analysis is the technique of choice due to its sensitivity and high reproducibility.
Guava's Caspase 8 and Caspase 3/7 assays detect the initial and mid-stages of programmed cell death, and, in conjunction with Guava's other cell death assays, allow researchers to more finely dissect the cellular suicide effects that drug compounds have on cells.
The assays offer a single cell analysis approach to assessing apoptotic status in a convenient microplate format. The assays employ a FLICA (Fluorescent Labelled Inhibitor of Caspases) reagent that specifically identifies active Caspase 3 and 7 molecules or Caspase 8 molecules. The nuclear DNA stain, propidium iodide (PI), is also included in the assay to simultaneously evaluate membrane integrity and cell viability.
Guava Caspase assays are ideally suited for applications in drug discovery and development. They are sensitive enough to detect even naturally occurring apoptosis at 2 to 6 per cent of the overall population, while still delivering robust, reproducible, and specific detection of Caspase 3/7 or 8 enzyme activity.
The CellGrowth assay, a cell proliferation assay, provides easy measurements of cellular division out to several generations. Current plate reader-based proliferation assays cannot detect if subpopulations within a sample are actively dividing or even alive.
The CellGrowth assay, when used in conjunction with the Guava EasyCyte System, provides cell proliferation analysis at the single-cell level, offering cell proliferation assessments out to 5 generations. In addition, the assay offers a broader linear range when compared to colorimetric methods.
The Guava CellGrowth Assay uses a cell tracking dye that diffuses freely into cells and is retained within the cell without affecting cellular function. The dye is not transferred to adjacent cells.
For each round of cell division, the relative fluorescence intensity of the dye is decreased by half. The assay is ideal for monitoring the growth of primary cultures, such as peripheral blood mononuclear cells (PBMCs), activated T or B cells, PBLs, thymocytes, hematopoietic cells, and fibroblasts.
The four new Guava assays all run on the Guava EasyCyte, a five-parameter system. Because only a few microlitres of sample are required, the Guava EasyCyte saves precious and expensive cells, reagents and compounds.
The system allows results to be generated with less than a day's training. The Guava EasyCyte system runs each of Guava's turnkey assays, enabling fast measurements of cell counting/viability; GFP expression and viability, apoptosis, cell cycle analysis, antigen detection and cell tracking.