Blue-laser micro-volume cell analysis system is capable of screening single cells for GFP expression in an automated 96-well plate format at the research bench
The new Guava PCA-96 AFP (auto-fluorescing protein) system allows researchers to determine the relative levels of fluorescing proteins produced by individual cells in a culture and to screen 96 such cultures in a single instrument run.
The compact system is said to be the only blue-laser, micro-volume cell analysis system capable of screening single cells for GFP expression in an automated 96-well plate format at the research bench.
Introduced this week at the Drug Discovery Technology meeting and exhibition in Boston, USA, Guava Technologies said that with the PCA-96 AFP, screening individual cells for green fluorescent proteins is now easier and quicker than ever.
"The fluorescence sensitivity, ease of use, and ability to analyse only microlitre volumes makes the new Guava quite versatile as a research instrument and a terrific addition to the Guava product line," said Lewis Lanier, professor of microbiology and immunology at the University of California, San Francisco.
"The Guava PCA-96 AFP system is really useful for analysing transformed cells that express GFP and detecting cells stained with both FITC-conjugated and PE-conjugated antibodies".
Like other Guava PCA systems, the PCA-96 AFP is compact, affordable and easy to use, requiring only microvolumes of cells and reagents and less than a day's training.
Naturally fluorescing proteins provide cell biologists with the means to track the expression, production and movement of proteins within living cells.
While GFP is the most commonly used fluorescent variant, proteins that fluoresce in the yellow, red and blue range are also in use.
The most commonly used variant of GFP for drug discovery and other mammalian cell research is most efficiently excited by light from a blue laser. Blue lasers are key components of flow cytometers, complex instruments that researchers can use for GFP expression studies to quantify the amount of a target protein expressed within a cell, on the cell surface, or within the supernatant from a cell culture.
However, use of flow cytometry in drug discovery research has been constrained due to the high instrument cost, difficulty of use, and the difficulty of scheduling experiment time on cytometers, which are maintained by specialised technicians in core facilities outside of most laboratories. Moreover, current 96-well microplate attachments for flow cytometers have been plagued by problems of significant sample carryover from well to well that greatly skew the accuracy and reliability of test results.
Fluorescent plate readers can detect GFP in microplates and can easily fit on benchtops but can only provide data on whole populations of cells rather than individual cells, thus limiting assay sensitivity.