Abstract:
A rapid method for the quantitation of various live cell types is described. The method may include a variety of steps including: 1) suspending the cells in a detergent-like compound; 2) isolating the washed cells by centrifugation or filtration; 3) resuspending the cells in a solution that contains a preservative, a fluorescent dye and a compound such as dequalinium which can be taken up by the cells; 4) measuring the fluorescence increase over time of the cell-dye mixture with a simple fluorometer; and 5) measuring the native fluorescence of the cells. This new cell fluorescence method correlates with other methods of enumerating cells such as the standard plate count, the methylene blue method and the slide viability technique. The method is particularly useful in several applications such as: a) quantitating bacteria in milk, yogurt, cheese, meat and other foods; b) quantitating yeast cells in brewing, fermentation and bread making; c) quantitating mammalian cells in research, food and clinical settings. The method is especially useful when both total and viable cell counts are required such as in the brewing industry. The method can also be employed to determine the metabolic activity of cells in a sample. The device, and/or system used for cell quantitation is also disclosed.
Abstract:
This invention describes methods and kits for quantifying viable cells in a sample using fluorescent dyes that can be internalized predominately by viable cells and have fluorescence properties measurably altered when bound to target components. These methods circumvent the need for training personnel in plating, growing and count viable cells, and reduce both the time and the cost required for cellular quantitation that use existing methods.
Abstract:
An assay system includes an optical imager to acquire high resolution images of assay strips (e.g., lateral flow immunochromatographic test strips) and performs image processing to identify individual assay strips and determine results for each assay strip, by quantifies the presence or absence of test signal line(s) and control signal line(s). Assay strips may be in a holder or carrier contained in a specimen container also holding a specimen. The assay system automatically logs all results and data to a database that stores a high resolution image of the original immunochromatographic assay, the values of test line(s) and control line(s), and the test result. A user interface directs an end user through operation.