3’-End labeled oligonucleotides can be used as sequence-specific protein binding or nucleic acid hybridization probes e.g. for EMSA, Northern or Southern blots. Compared to internal, random labeled probes, the label is located at the 3‘-End only and less likely interferes with probe binding.
The combination of (poly)-HRP-conjugated Biotin/Digoxigenin detection reagents with AF 488 (Alexa Fluor® 488)-, AF546 (Alexa Fluor® 546)- or AF594 (Alexa Fluor® 594)-labeled tyramide further increases detection sensitivity of up to 100-fold.
Figure 1 Terminal deoxynucleotidyl Transferase (TdT) template-independently transfers labeled nucleotides to the 3’-OH group of ssDNA/oligonucleotides. The number of nucleotide and thus label incorporation depends on the type of nucleotide ((dd)UTP) and type of label (n = 1 for labeled ddUTP, n = 1 - 3 (average) for labeled UTP, n > 1 for labeled dUTP (multiple label, tail length is highly nucleotide specific).
|Kit||Label||# of Label||Labeling principle similar to …|
|BIO 3‘-End Oligonucleotide Labeling Kit with Biotin-11-UTP||Biotin||1-3||Biotin 3‘-End DNA Labeling Kit (Pierce/Thermo Scientific)|
|DIG 3‘-End Oligonucleotide Labeling Kit with Digoxigenin-11-ddUTP||Digoxigenin||1||DIG Oligonucleotide 3‘ End Labeling Kit, 2nd generation (Roche)|
|3‘-End Oligonucleotide Labeling Reagent Kit||nucleotide dependent||nucleotide dependent||-|