Cyanine5.5hydrazideisacarbonyl-reactivenearinfrareddye.Hydrazidesquicklyreactwithcarbonylcompounds,suchasaldehydesandketones,andformstablehydrazones.Thisreactionisusefulforthepreparationoflabeledconjugates.
Carbonylgroupsinbiomoleculescanformspontaneouslyafteroxidativestressordeaminationofproteins.Alternatively,aldehydegroupscanbespecificallygeneratedbyperiodateoxidationofsugarresiduesofglycoproteins,forexampleantibodies.AntibodiescanbeoxidizedbysodiumperiodateandlabeledwithCyanine5.5hydrazidetoformCyanine5.5labeledantibodies.Sincesugarresiduesinantibodiesarelocatedfarfromvariable,epitope-bindingsite,thismethodisparticularlygoodforthelabelingofantibodies.
Cyanine5.5isanearinfraredfluorophore,ananalogofCy5.5®.Itisparticularlysuitablefortheapplicationswhichrequirelowfluorescencebackground.Theabsorptionandemissionwavelengthofthedyeexhibitsignificanttissuepenetration,soCyanine5.5issuitableforinvivoNIRimagingapplications.
Generalproperties
| Appearance: | darkbluepowder | 
| Molecularweight: | 669.73 | 
| Molecularformula: | C40H46Cl2N4O | 
| Solubility: | moderatesolubilityinwater,goodinpolarorganicsolvents(DMF,DMSO,alcohols) | 
| Qualitycontrol: | NMR1H,HPLC-MS(95%) | 
| Storageconditions: | Storage:24monthsafterreceivalat-20°Cinthedark.Transportation:atroomtemperatureforupto3weeks.Avoidprolongedexposuretolight.Desiccate. | 
Spectralproperties
| Excitationmaximum,nm: | 684 | 
| ε,L⋅mol−1⋅cm−1: | 209000 | 
| Emissionmaximum,nm: | 710 | 
| Fluorescencequantumyield: | 0.2 | 
| CF260: | 0.07 | 
| CF280: | 0.03 |