A new violet-excited organic dye called Krome Orange expands the range of available choices and dye sensitivity limits for violet lasers. Common gating markers can be easily transferred to this fluorochrome, freeing other channels for use with more esoteric markers and enabling more versatile 10-colour flow cytometry applications. The product has excitation and emission maxima of 398 nm and 528 nm respectively. It conjugates show optimal performance with violet laser excitation and a 550/40 bandpass filter (the standard FL10 channel on flow cytometry systems), while no excitation is detected using a 488 nm laser.
In the image, Krome Orange dye excitation curve (dashed black line); emission curves for Krome Orange dye, Pacific Orange dye, AmCyan, and V500 dye. The shaded region represents the standard 550/40 bandpass filter installed into FL10 on a cytometer.