Stochastic model of the response of labeled microspheres and B cells during the analysis by a flow cytometer

Published

July 31, 2021

Author(s)

Adolfas Gaigalas, Yu-Zhong Zhang, Linhua Tian, Lili Wang

Abstract

A stochastic model of the flow cytometer measurement process was developed to understand the nature of the observed coefficient of variation (CV%) of the mean fluorescence intensity (MFI) from labeled receptors on a B cell population. The current version of the model was developed using a model system of labeled microspheres(beads). Two types of random variables were identified. The first type is fixed for a given bead but varies over the beads in the population. Examples of the first type are the total number of labels on a bead, and the path and/or radius of the bead. The second type of variable varies for a given bead but the average over a bead is relatively constant over the beads in the population. Examples of the second type are the quantum yield of a label, and the polarization of the transition dipole moment of the label. The CV% of variables of the first type have a large effect on the CV% of the MFI of the bead population. In contrast, The CV% of variables of the second type have a much smaller effect. The variation in path of the bead through the laser beam is small for modern flow cytometers, leaving the number of labels on the bead as the main contributor to the observed CV%. The stochastic model of the labeling process of cells indicated that the number of labeled mAb on the cell depended on the number of receptors on the cell and the relative strength of the monovalent and bivalent binding of the mAb to the receptors. The results of the initial application of the stochastic model to beads suggest that the observed CV% of a flow cytometer measurement of cells are mostly due to the fluctuation in the number of labeled receptors on the cells.

Citation

International Journal of Molecular Sciences

Pub Type

Journals

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Keywords

Flow cytometer, Stochastic model, Mean fluorescence intensity (MFI), coefficient of variation (CV%), The number of labels

Citation

Gaigalas, A. , Zhang, Y. , Tian, L. and Wang, L. (2021), Stochastic model of the response of labeled microspheres and B cells during the analysis by a flow cytometer, International Journal of Molecular Sciences, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=932670 (Accessed April 19, 2025)