Terminal Deoxynucleotidyl Transferase (Tdt)

Applications

• Prefered substrates are single-stranded DNA, double-stranded DNA with 3’-hydroxyl termini and oligodeoxynucleotide primers (1)
• Used for specific labeling of 3'-termini with ribonucleotides (2)
• Labels 3'-ends of DNA fragments with an [α-³²P] 3'-deoxynucleoside (3)
• Adds homopolymer tails of deoxyribonucleotides to vectors or cDNAs (4,5)

Reagents Supplied

5X Tdt C-Tailing Reaction Buffer

Unit Definition

One unit is the amount of enzyme required to transfer 1 nmol of dAMP from dATP to the 3' OH terminus of the oligonucleotide initiator d(A)15 for 1 hour at 37ºC

Heat Inactivation

15 minutes at 75ºC

Concentration

10-15 units/µl

Storage Buffer

50 mM Potassium Phosphate (pH 7.4) 
1 mM β-mercaptoethanol
50% (w/v) Glycerol

Assay Conditions

40 mM K Cacodylate (pH 7.2)
8 mM MgCl₂
0.33 mM ZnSO₄
10 µM Oligonucleotide d(A)₅₀
10 µl Bovine Serum Albumin
1 mM (α-³²P) dATP
Reaction volume of 60 µl

Note: All reactions should be run in polypropylene tubes

Storage Conditions

Store at -20°C
Product shipped on Dry Ice