ANTIBODY TITER ASSESSMENT BY IMAGE CYTOMETRY

"In order to prevent the spread of viral infections or to assess the effectiveness of vaccination, there is an urgent need for methods to quickly identify and characterize possible treatment options. The serological methods, commonly used for antibody titration, are informative yet the data provided are sometimes limited. Imaging cytometry can be an effective approach for characterizing potential therapeutic antibodies to combat viral infections.Using an indirect immunofluorescence test, based on BIOCHIP technology to detect anti-yellow fever virus IgG, we realized a calibration curve based on dilution of a positive control serum and a blood sample obtained from a person who has received the yellow fever vaccine. The obtained images were then analysed by image cytometry which involved: image pre-processing, removal of the cell nucleus considered to be the most representative for measurement, indirect measurement of five times the specific corrected total cellular fluorescence (CTCF) for each representative cell and calculation of the average CTCF value. We calculated the mean CTCF values for each condition and correlated the CTCF value with the antibody titer, according to the manufacturer's recommendations.Image cytometry has the ability to rapidly determine the direct binding of antibodies to host cells and can be applied to study other pathogen-antibody interactions, thus impacting future research on viral pathogens."