Beckman Coulter has launched Krome Orange, a violet-excited organic dye that is said to expand 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 cytometry applications.
Krome Orange has excitation and emission maxima of 398nm and 528nm respectively and provides a brighter signal than Pacific Orange conjugates with equivalent spectral overlaps into adjacent channels.
The dye is at least as bright as V500 and can provide more than twice the population separation obtained with Pacific Orange dye conjugates, with little compensation compared with Pacific Blue dye.
Krome Orange 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 488nm laser.
The initial release of Krome Orange includes conjugates to human CD45 and CD4, with the range of human and mouse targets to expand going forward.
Brad Calvin, vice-president and general manager of the Beckman Coulter Flow Cytometry Business Centre, said: 'Krome Orange provides scientists with the ability to increase sensitivity for low fluorescence signals and to expand their flexibility for multi-colour flow cytometry experiments.'
