HiLyte Fluor™ 488-IgY conjugate has been optimized in fluorophore/protein labeling ratio to ensure high fluorescent signal and uncompromised IgY function. HiLyte Fluor™ 488 is a green flurophore with brighter fluorescence and better photostability than fluorescein, such as FITC. The spectrum of HiLyte Fluor™ 488 is similar to FITC, resulting in an optimal match to filters designed for fluorescein. The fluorescence of HiLyte Fluor™ 488 can be observed at excitation/emission wavelength of 499 nm/523 nm.