brightness dye > quantum dot > fluorescence protein
photo stability duantum dot >> dye > fluorescnece protein
2 ways to label protein 2 specfic chemistry amide mal-s
new chemistry to replace mal-s way to reduce the electron pair on sulfur “pod” pod imporve photostability of cyanines
photoxicity sun 0.01-0.1 W/cm2 epi-fluorecence 0.1-1 W/cm2 spinning disk confocal 0.05-5 W/cm2 PALM/STORM 5-9 k W/cm2 STED 20-50 M W/cm2 raman is even higher
triplet state (lifetime 1μs~1ms) long lasting radicals
Cy3 with Trolox / NB / COT to prevent triplet
these dyes are hydrophobic cation so it can target mitochondria (proton gradient driven atp synthesis)
rhodamine dye can also be enhanced with COT (why rhodamine, neutral and not fluorescencet until binding)
photobleaching and photoxicity is not always linked