Activity of DNA Modifying Enzymes in rCutSmart™ Buffer

We are excited to announce that all reaction buffers are now BSA-free. NEB began switching our BSA-containing reaction buffers in April 2021 to buffers containing Recombinant Albumin (rAlbumin) for restriction enzymes and some DNA modifying enzymes. Find more details at

Enzyme Activity in rCutSmart Buffer Required Supplements*
Antarctic Phosphatase +++  Requires Zn2+
Authenticase ++  
Bst DNA Polymerase +++  
CpG Methyltransferase (M. SssI) +++  
DNA Polymerase I +++  
DNA Polymerase I, Large (Klenow) Fragment
DNA Polymerase Klenow Exo- +++  
DNase I (RNase-free) +++ Requires Ca2+
DNase I-XT
 +++ Requires Ca2+
Duplex DNase +  
E. coli DNA Ligase +++ Requires NAD
Exonuclease I
Thermolabile Exonuclease I
Exonuclease III +++  
Endonuclease III (Nth), recombinant +++  
Exonuclease V (Rec BCD)  +++ Requires ATP
Exonuclease VII +++
Endonuclease VIII  +++  
Fpg  +++   
GpC Methyltransferase (M. CviPI) + Requires DTT
Lambda Exonuclease  ++  
Micrococcal Nuclease +++ Requires Ca2+
Mismatch EndoI ++  
Thermostable OGG
phi29 DNA Polymerase +++ Requires DTT
RecJf +++  
rSAP +++  
Quick CIP
T3 DNA Ligase +++ Requires ATP + PEG
T4 DNA Ligase +++ Requires ATP
Hi-T4™ DNA Ligase +++ Requires ATP
Salt-T4® DNA Ligase + Requires ATP
T4 DNA Polymerase +++  
T4 Phage β-glucosyltransferase (T4-BGT) +++  
T4 Polynucleotide Kinase +++ Requires ATP + DTT
T4 PNK (3 ' phosphatase minus) +++ Requires ATP + DTT
T5 Exonuclease  +++  
T7 DNA Ligase +++ Requires ATP + PEG
T7 DNA Polymerase (unmodified) +++
T7 Exonuclease +++  
USER® Enzyme, recombinant
Thermolabile USER II
Thermostable USER III
Warmstart Afu UDG +  

*Refer to “Reaction Conditions” on product webpage for recommended supplement concentration

+++ full functional activity
++ 50-100% functional activity
+ 0-50% functional activity