3′-End Oligonucleotide Labeling Reagent Kit

3′-End Oligonucleotide Labeling Reagent Kit contains all buffer reagents required for efficient 3′-End Labeling of DNA oligonucleotides (length: 20 -100 bp, 5 pmol per reaction) except of oligonucleotide template to be labeled and labeled nucleotides.. The labeling principle is based on Terminal deoxynucleotidyl Transferase (TdT) that template-independently transfers labeled nucleotides to the 3′-OH group of ssDNA (e.g. an oligonucleotide) in the presence of CoCl2. The number of nucleotide and thus label incorporation depends on the type of nucleotide (UTP/ddUTP) and type of label. Labeled UTP: 1 – 3 label (average) Labeled dUTP: multiple label (tail length is highly nucleotide specific) Labeled ddUTPs: 1 label The resulting 3′-End labeled oligonucleotides are ideally suited for applications involving sequence-specific protein binding or hybridiziation such as 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. TdT possesses a preference for single-stranded DNA (ssDNA) over dsDNA with 3′-overhangs or blunt ends. For the preparation of labeled dsDNA complexes, label each complementary oligonucleotide separately and anneal them before use.