We are looking for beads (max size 0.5uM) to discriminate under a fluorescent microscope active vs. moulting C. elegans worms (the active ones will eat the beads in the medium together with the bacteria and the beads will be visible in the gut of the worms).
There is a publication with the beads referenced just below, but there spectra is too much overlapping with our fluorophores:
Do you know any alternative in the blue or far-red range? Invitrogen sells 175nm beads in this range, I just fear they are too small and/or not bright enough for our imaging conditions (imaging with 20x/0.8 air objective).
Thanks in advance for your help,