IRDye 750-NHS

IR750-NHS is a near-IR fluorescent dye used for labeling oligonucleotides. IR750 has an absorbance maximum of 756 nm and an emission maximum of 776 nm. The combination of narrow absorbance/emission bands and low-background autofluorescence in the IR region results in higher S/N ratios and thus enhanced detection sensitivity compared with fluorophores with absorbance/emission maxima in the visible region (1). IRDye750 is used as a reporter moiety in real-time PCR applications. For such probes, IRDye750 is most commonly paired with the dark quencher QC-1, as the two have excellent spectral overlap (2).

IRDye750 can be used to label DNA oligos for use as hybridization probes in a variety of in vivo and in vitro research or diagnostic applications, as well as for structure-function studies of DNA, RNA, and protein-oligonucleotide complexes. Oligos labeled with IRDye750 at the 5’-end can be used as PCR and Sanger DNA sequencing primers to generate fluorescently-labeled PCR, sequencing or genetic analysis (AFLP, microsatellite) products (3-5).

Near Infrared Fluorophore Spectral Data & Quencher Selection Guide
Fluorophore Name	Excitation Max, nm +/-10	Emission Max, nm +/-10	Extinction Coefficient*	Color**	Quencher
Cy5	650	665	250,000	Human vision is insensitive to light beyond ~650 nm.	BBQ-650 λ (max) = 650nm Range = 550-750 nm
IRDye 650 NHS	650	665	230,000	Human vision is insensitive to light beyond ~650 nm.	BBQ-650 λ (max) = 650nm Range = 550-750 nm
AZ647 NHS	655	680	191,800	Human vision is insensitive to light beyond ~650 nm.	BBQ-650 λ (max) = 650nm Range = 550-750 nm
Cy5.5	684	710	198,000	Human vision is insensitive to light beyond ~650 nm.	BBQ-650 λ (max) = 650nm Range = 550-750 nm
IRDye 700 NHS	684	710	288,000	Human vision is insensitive to light beyond ~650 nm.	BBQ-650 λ (max) = 650nm Range = 550-750 nm
Cy7 NHS	740	773	199,000	Human vision is insensitive to light beyond ~650 nm.	BBQ-650 λ (max) = 650nm Range = 550-750 nm
IRDye 750 NHS	756	776	260,000	Human vision is insensitive to light beyond ~650 nm.	BBQ-650 λ (max) = 650nm Range = 550-750 nm
cy7.5 NHS	788	808	223,000	Human vision is insensitive to light beyond ~650 nm.	BBQ-650 λ (max) = 650nm Range = 550-750 nm
IRDye 800 NHS	795	819	240,000	Human vision is insensitive to light beyond ~650 nm.	BBQ-650 λ (max) = 650nm Range = 550-750 nm
* Extinction coefficient at λ (max) in cm-1M-1. ** Typical emission color seen through the eyepiece of a conventional fluorescence microscope with appropriate filters. Near-IR region. Human vision is insensitive to light beyond ~650 nm; it is not possible to view near-IR fluorescent dyes. Click here for a list of fluorophores.
Click here for list of quenchers.

References
1. Middendorf, L.R., Bruce, J.C., Eckles, R.D., Grone, D.L., Roemer, S.C., Sloniker, G.D., Steffens, D.L., Sutter, S.L., Brumbaugh, J.A., et al. Continuous, on-line DNA sequencing using a versatile infrared laser scanner/electrophoresis apparatus. Electrophoresis (1992), 13: 487-494.
2. Peng X., Chen, H., Draney, D.R., Volcheck, W., Schutz-Geschwender, A., Olive, D.M. A nonfluorescent, broad-range quencher dye for Forster resonance energy transfer assays. Anal. Biochem. (2009), 388: 220-228.
3. Yomano, L.P., Scopes, R.K., Ingram, L.O. Cloning, sequencing, and expression of the Zymomonas mobilis phosphoglycerate mutase gene (pgm) in Escherichia coli. J. Bacteriol. (1993), 175: 3926-3933.
4. Oetting, W.S., Lee, H.K., Flanders, D.J., Wiesner, T.A., King, R.A. Linkage Analysis with Multiplexed Short Tandem Repeat Polymorphisms Using Infrared Fluorescence and M13 Tailed Primers. Genomics (1995), 30: 450-458.
5. Myburg, A.A., Remington, D.L, O’Malley, D.M., Sederoff, R.R., Whetton, R.W. High-Throughput AFLP Analysis Using Infrared Dye-Labeled Primers and an Automated DNA Sequencer. Biotechniques (2001), 30: 348-357.
- IRDye 750-NHS