TCO(tetrazine–trans-cyclooctene)ligationisoneofthefastestreactionsusedforbioconjugation.Itisaninverseelectrondemand[4+2]cycloadditionthattakesplacebetweentetrazineandtrans-cycloocteneorotherstrainedolefin.
Sulfo-Cyanine5tetrazineisafluorophorederivativebearingatetrazinegroupfortheTCO-ligationbasedlabeling.
ThisreagentpossessesgoodaqueoussolubilityandstABIlityinBIOLOGicalenvironments.
Generalproperties
| Appearance: | darkbluesolid | 
| Molecularweight: | 864.09 | 
| Molecularformula: | C42H46KN7O7S2 | 
| Solubility: | goodinwater,DMF,DMSO | 
| Qualitycontrol: | NMR1H,HPLC-MS(95%) | 
| Storageconditions: | Storage:24monthsafterreceivalat-20°Cinthedark.Transportation:atroomtemperatureforupto3weeks.Avoidprolongedexposuretolight.Desiccate. | 
Spectralproperties
| Excitationmaximum,nm: | 646 | 
| ε,L⋅mol−1⋅cm−1: | 271000 | 
| Emissionmaximum,nm: | 662 | 
| Fluorescencequantumyield: | 0.28 | 
| CF260: | 0.04 | 
| CF280: | 0.04 |