Infrared Fluorescent-Based Reagents
for Gel Shift Assays
Gel shift assays, or electrophoretic mobility shift assays (EMSA), provide a simple method to study DNA-protein interactions. Existing mobility shift assay protocols can be easily converted to infrared fluorescent assays by replacing the existing DNA oligonucleotides with IRDye® infrared dye end-labeled oligonucleotides. Binding and electrophoresis conditions are the same as any other EMSA detection method.
A DNA oligonucleotide end-labeled with IRDye 700 infrared dye is a good substrate for protein binding. Using the Odyssey Infrared Imaging System, IRDye infrared dye labeled DNA detection is linear within a 50-fold dilution range from 9.1 fmol to 0.18 fmol. Infrared assays can be completed in less than two hours with no gel transfer or film exposure. The gel doesn’t even have to be removed from the glass plates for imaging. Plus, the gel can be placed back into the electrophoresis unit and run longer, if necessary.
| Advantages of Infrared |
| Infrared |
Radioisotope |
| Easy access and disposal |
Regulatory procedures
Disposal limitations |
Dye is stable for a long time
|
Short half-life of the label |
| Non-hazardous |
Hazardous |
| Gel (glass plates) can be easily
imaged on the Odyssey |
Lengthy incubations with autoradiographic
film |
| Detection of the probe is rapid |
Time-consuming and inconvenient |
| Gel can be replaced back and run
longer |
Not possible |
IRDye 700 infrared dye-labeled EMSA oligonucleotides are supplied as 25 µl of 50 nM double-stranded DNA
Please note: Oligos with an * require up to two weeks for processing and delivery.
Ordering Information
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