New England Biolabs, M0262L, Lambda Exonuclease

Related Categories Exonucleases and Non-specific Endonucleases Specification Unit Definition One unit is defined as the amount of enzyme required to produce 10 nmol of acid-soluble deoxyribonucleotide from double-stranded substrate in a total reaction volume of 50 μl in 30 minutes at 37°C in 1X Lambda Exonuclease Reaction Buffer with 1 μg sonicated duplex [ 3 H]-DNA. Reaction Conditions 1X Lambda Exonuclease Reaction Buffer Incubate at 37°C 1X Lambda Exonuclease Reaction Buffer 67 mM Glycine-KOH 2.5 mM MgCl2 50 µg/ml BSA (pH 9.4 @ 25°C) Usage Concentration 5,000 units/ml Storage Buffer 25 mM Tris-HCl 50 mM NaCl 1 mM DTT 0.1 mM EDTA 50% Glycerol pH 8 @ 25°C Heat Inactivation 75°C for 10 minutes Molecular Weight Theoretical: 28000 daltons Specific Activity 50,000 units/mg FAQ Q: What is the activity of M0262 Lambda Exonuclease in various NEB buffers? A: The activity of Lambda Exonuclease in various buffers is listed below: NEBuffer 1 - 15% NEBuffer 2 - 40% NEBuffer 3 -10% NEBuffer 4 - 40% CutSmart – 50% Exonuclease I Reaction Buffer- 100% Thermopol Reaction Buffer -100% Q: How Does T5 Exonuclease differ from Lambda Exonuclease (NEB# M0262)? A: Unlike Lambda Exonuclease, T5 Exonuclease can degrade nicked-circular dsDNA. T5 Exonuclease also acts on ssDNA, while Lambda Exonuclease does not. Q: How Does T7 Exonuclease differ from Lambda Exonuclease (NEB# M0262)? A: T7 Exonuclease has even less activity on single stranded DNA than Lambda Exonuclease, acts at nicks unlike Lambda Exonuclease, and is less processive. Since it is less processive it may be more useful for unidirectional nested deletions. The enzyme can be diluted to control the reaction rate. With a highly processive enzyme, like Lambda Exonuclease, dilution gives a mix of completely digested products and undigested substrate. Q: Will Lambda Exonuclease work in rCutSmart Buffer? A: Lambda exonuclease will work in rCutSmart Buffer. To see its % functional activity in rCutSmart, and that of other DNA modifying enzymes in the cloning workflow, refer to the Activity of DNA Modifying Enzymes in rCutSmart® Buffer chart. Q: Can Exonuclease I be used with a double stranded exonuclease to clean up plasmid preparations? A: Exonuclease I can be used with Lambda Exonuclease (NEB# M0262) to clean up plasmid preps. Exonuclease III (NEB# M0206) and T7 Exonuclease (NEB# M0263) will also work, but will damage nicked plasmids. Although Exonuclease I can be used, we recommend using Exonuclease V (RecBCD) (NEB #M0345) to remove chromosomal DNA after plasmid prep (see our Application Note: Using Exonuclease V (RecBCD) to Eliminate Residual Genomic DNA When Purifying Low Copy Plasmids with the Monarch® Plasmid Miniprep Kit.