Which dye/color combination is commonly used to measure anti-donor antibodies in the flow crossmatch?

The combination of FITC (Fluorescein Isothiocyanate) and Green is commonly utilized in flow cytometry for measuring anti-donor antibodies during a crossmatch test. FITC is a fluorescein derivative that emits bright green fluorescence when excited by a specific wavelength of light, typically provided by a laser in flow cytometry. When determining compatibility between donor and recipient, this fluorescent labeling enables the identification of antibodies binding to the donor cells.

In the context of flow crossmatching, the presence of anti-donor antibodies can lead to the formation of immune complexes, which, when bound to FITC-labeled donor cells, will fluoresce and be detected by the flow cytometer, serving as an indicator of potential incompatibility. This method provides a sensitive and quantitative approach to assessing the reactivity of recipient serum antibodies against donor cells, helping prevent transplant rejection.

The other dye/color combinations mentioned serve different purposes or use different detection principles. For instance, PE (Phycoerythrin) tagged antibodies might produce different fluorescence characteristics and may not be as effective for this specific application. Ethidium Bromide is more associated with nucleic acid staining and not relevant for detecting antibodies in a crossmatch setting. Therefore, the use of FIT