Kinetics of the initial stage of immunoagglutionation studied with the scanning flow cytometer

TL;DR

This study uses a scanning flow cytometer to analyze the early stages of immunoagglutination by measuring light-scattering patterns of latex particles, validating a diffusion-limited aggregation model with experimental data.

Contribution

It introduces a novel application of SFC for real-time analysis of immunoagglutination and validates a mathematical model of the process.

Findings

SFC effectively discriminates particle types during immunoagglutination.

Experimental data aligns well with the diffusion-limited aggregation model.

The method allows detailed study of early immunoagglutination kinetics.

Abstract

The use of a scanning flow cytometer (SFC) to study the evolution of monomers, dimers and higher multimers of latex particles at the initial stage of the immunoagglutination is described. The SFC can measure the light-scattering pattern (indicatrix) of an individual particle over an angular range of 10-60 deg. A comparison of the experimentally measured and theoretically calculated indicatrices allows one to discriminate different types of latex particles (i.e. monomers, dimers, etc.) and, therefore, to study the evolution of immunoagglutination process. Validity of the approach was verified by simultaneous measurements of light-scattering patterns and fluorescence from individual polymer particles. Immunoagglutination was initiated by mixing bovine serum albumin (BSA)-covered latex particles (of 1.8 um in diameter) with anti-BSA IgG. The analysis of experimental data was performed on the basis of a mathematical model of diffusion-limited immunoagglutination aggregation with a steric factor. The steric factor was determined by the size and the number of binding sites on the surface of a latex particle. The obtained data are in good agreement with the proposed mathematical modeling.