Bead Count Rate
Bead Count Rate - Related Videos
10:19
Using a Hemacytometer to Count Cells
0 Views •
2023
Many biomedical experiments require manipulation of a known quantity of cells, in order to achieve accurate, reproducible, and statistically-relevant data. Therefore, learning how to count cells is a particularly essential technique for any successful biomedical scientist. The most common way to count cells is by using a hemacytometer - an instrument that bears two laser-etched grids, which aid in the enumeration of an aliquot cells under a simple light microscope. This data can then be used to...
05:47
Counting and Determining the Viability of Cultured Cells
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Cited by 19 •
2008
Determining the number of cells in culture is important in standardization of culture conditions and in performing accurate quantitation experiments. In this video, we demonstrate how cells are counted using a hemacytometer.
14:14
Optimized Fibrin Gel Bead Assay for the Study of Angiogenesis
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Cited by 166 •
2007
This video demonstrates the protocol of an in vitro angiogenesis assay that recapitulates several stages of angiogenesis. Time-lapse images of sprouting, lumen formation, branching and anastomosis - key features of angiogenesis - are shown.
12:25
Counting Proteins in Single Cells with Addressable Droplet Microarrays
0 Views •
Cited by 2 •
2018
Here we present addressable droplet microarrays (ADMs), a droplet array based method able to determine absolute protein abundance in single cells. We demonstrate the capability of ADMs to characterize the heterogeneity in expression of the tumor suppressor protein p53 in a human cancer cell line.
06:37
Counting Human Neural Stem Cells
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Cited by 14 •
2007
Knowledge of the exact number of viable cells is required for many tissue culture manipulations. This protocol describes how to differentiate between live and dead cells and quantify cells using a hemacytometer. Although it describes counting human neural stem/precursor cells (hNSPCs), it can be used for other cell types.
FAQs
Each bead passing through the interrogation point produces an optical event that can be detected and counted. Examining the number of events acquired during a defined time interval provides information about whether particle passage and data acquisition remain consistent. This makes bead count rate useful for identifying variation in fluidics or acquisition between samples and experimental runs.
A bead count rate becomes more informative when the bead concentration is known and standardized. The measured events can then be related to the amount of sample processed, rather than treated as an isolated instrument value. This relationship supports comparisons across runs and contributes to absolute quantification when sample volume is also known.
Bead Count Rate primarily provides a standardized reference for particle acquisition, whereas immune cells, pathogens, or other sample particles may vary in number between specimens. Because the beads are standardized, their event rate can help evaluate acquisition consistency independently of the biological content. This distinction separates instrument monitoring from interpretation of the sample population itself.
Interpretation depends on consistent bead concentration, the time interval used for counting, and the sample volume associated with the acquisition. These conditions determine how event counts can be compared across samples or runs. Maintaining comparable conditions strengthens the value of the measurement for quality control and for calculations involving absolute particle numbers.
A basic workflow begins with fluorescent beads suspended in the sample, followed by acquisition in a flow cytometer as the particles pass the interrogation point. The resulting bead events are counted over a defined time period and compared across samples or runs. Known bead concentration and sample volume can then support absolute quantification of target particles.
Absolute quantification is supported when the bead concentration and the sample volume are known, allowing bead-based acquisition data to serve as a reference for particle numbers. In immunology and infection studies, this approach can be applied to immune cells, pathogens, or other particles. It is especially useful when comparisons require counts rather than only relative signal.
Researchers can compare bead count rates among samples or experimental runs to assess the consistency of fluidics and data acquisition. Similar acquisition conditions make these comparisons more meaningful, while variation can indicate that the measurement process is not equally consistent across runs. Monitoring the rate therefore strengthens confidence in downstream comparisons and quantification.