New England Biolabs, R0194S, XmnI

XmnI has been reformulated with Recombinant Albumin (rAlbumin) beginning with Lot #10119487. Related Categories Restriction Endonucleases T Z,, Time-Saver Qualified Restriction Enzymes Applications Restriction Enzyme Digestion Specification Unit Definition One unit is defined as the amount of enzyme required to digest 1 µg of λ DNA in 1 hour at 37°C in a total reaction volume of 50 μl. Reaction Conditions 1X rCutSmart™ Buffer Incubate at 37°C 1X rCutSmart™ Buffer 50 mM Potassium Acetate 20 mM Tris-acetate 10 mM Magnesium Acetate 100 µg/ml Recombinant Albumin (pH 7.9 @ 25°C) Activity in NEBuffers NEBuffer™ r1.1: 50% NEBuffer™ r2.1: 75% NEBuffer™ r3.1: <10% rCutSmart™ Buffer: 100% Diluent Compatibility Diluent A Storage Buffer 10 mM Tris-HCl 50 mM KCl 1 mM DTT 0.1 mM EDTA 200 µg/ml Recombinant Albumin 50% Glycerol pH 7.4 @ 25°C Heat Inactivation 65°C for 20 minutes Methylation Sensitivity dam methylation: Not Sensitive dcm methylation: Not Sensitive CpG Methylation: Not Sensitive FAQ Q: Do degenerate recognition sites need to be palindromic? A: Most restriction enzyme recognition sites are palindromic and include only specified base pairs (i.e., EcoRI recognizes GAATTC). However, some enzymes have degenerate sites, meaning that they contain one or more base pairs that are not specifically defined (i.e., BsrFI-v2 recognizes RCCGGY, where R= A or G and Y= C or T). For degenerate enzymes, any base represented by the single letter code may be present at either location in the recognition site for cleavage to occur. For example, BsrFI-v2 recognizes all of the following sequences: ACCGGC, ACCGGT, GCCGGC, GCCGGT. Q: What is Star Activity and how can it be avoided? A: It has been demonstrated that under extreme non-standard conditions, restriction endonucleases are capable of cleaving sequences which are similar but not identical to their defined recognition sequence. This altered or relaxed specificity has been termed ""star"" activity. It has been suggested that star activity may be a general property of restriction endonucleases and that any restriction endonuclease can be made to cleave noncanonical sites under certain extreme conditions. The manner in which an enzyme's specificity is altered depends on the enzyme and on the conditions employed to induce the star activity. The most common types of altered activity are single base substitutions, truncation of the outer bases in the recognition sequence, and single-strand nicking. Star activity is completely controllable in the vast majority of cases and is generally not a concern when performing restriction endonuclease digests. New England Biolabs' enzymes will not exhibit star activity when used under recommended conditions in their supplied NEBuffers. Listed below are reaction conditions known to induce or inhibit star activity. Conditions that Contribute to Star Activity 1. High glycerol concentration [> 5% v/v] 2. High units to µg of DNA ratio [Varies with each enzyme, usually >100 units/µg] 3. Low ionic strength [< 25 mM] 4. High pH [> pH 8.0] 5. Presence of organic solvents [DMSO, ethanol, ethylene glycol, dimethylacetamide, dimethylformamide, sulphalane] 6. Substitution of Mg++ with other divalent cations [Mn++, Cu++, Co++, Zn++] Inhibiting Star Activity If you are concerned about star activity, we recommend the following guidelines. 1. Use as few units as possible to get a complete digestion. This avoids overdigestion and reduces the final glycerol concentration in the reaction. 2. Make sure the reaction is free of any organic solvents such as alcohols which might be present in the DNA preparation. 3. Raise the ionic strength of the reaction buffer to 100-150 mM (provided the enzyme is not inhibited by high salt). 4. Lower the pH of the reaction buffer to pH 7.0. 5. Use Mg++ as the divalent cation. Q: Do I have to set-up digests with Time-Saver™ qualified enzymes for 5-15 minutes? Can I digest longer? A: NEB's Time-Saver™ enzymes have the benefit of working fast (5-15 minutes), but are also designed and qualified to withstand overnight digestions without degradation of DNA. Q: I tested your restriction enzyme on the substrate DNA recommended by NEB, and it appears to be active, however it does not digest my DNA. What could be the reason? A: The quality and cleanliness of the DNA are major factors that can affect enzyme activity. Restriction Enzymes active in rCutSmart® Buffer, but not as active in NEBuffer r2.1 and/or r3.1 (our higher salt buffers), can be inhibited by salt in the reaction. DNA purification procedures that use spin columns can result in DNA solutions with significant levels of salt that can carry over into the reaction and inhibit enzyme activity. To prevent this, we recommend that the DNA solution added to the reaction be no more than 25% of the total reaction volume. This can be attained by adjusting the total reaction volume accordingly. Q: Which NEB restriction enzymes are supplied with Gel Loading Dye, Purple (6X)? A: All HF-restriction enzymes and most NEB non-HF restriction enzymes are supplied with Gel Loading Dye, Purple (6X). The non-HF restriction enzymes that come supplied with purple dye are: AatII AsiSI BsmBI-v2 EagI MboI NlaIII PvuI SmaI Acil AvrII BspHI EcoRI MboII NotI RsaI SpeI AfeI BamHI BsrGI EcoRV MluI NspI SacI StuI AflII BbsI ClaI Esp3I FseI MseI PacI SacII AgeI BglII DdeI HaeIII MspI PciI SalI XbaI AluI BsaI DpnI HindIII NcoI PmeI SapI XhoI ApaI BseYI DpnII HpaI NdeI PsiI-v2 SfaNI XmaI ApeKI BsiWI DraI KpnI NheI PstI SfiI XmnI AscI * All HF restriction enzymes are also supplied with Gel Loading Dye, Purple (6X) Q: Is this enzyme sensitive to dam, dcm or mammalian CpG methylation? A: No. This enzyme is not sensitive to dam, dcm, or mammalian CpG methylation. For up-to-date information about methylation sensitivities, please visit Dam-Dcm and CpG Methylation or REBASE. Q: Does NEB offer any BSA-free and/or animal origin-free restriction enzymes for linearization of plasmids for mRNA vaccine development? A: Yes, NEB has formulated some restriction enzymes (including BspQI, an SapI isoschizomer) without animal-derived components and no BSA appears in their final formulation. In addition, we have several restriction enzymes available without BSA nor other animal-derived components in their final formulation. This list includes: BbsI-HF BsaI-HFv2 BspQI, isoschizomer of LguI, GMP-grade* now available BspQI-HF ClaI HindIII-HF PacI SapI SpeI SwaI XbaI XhoI XmnI Other enzymes can be formulated upon request. Please inquire here. * “GMP Grade” and “GMP-grade” are branding terms NEB uses to describe products manufactured or finished at NEB’s Rowley facility. The Rowley facility was designed to manufacture products under more rigorous infrastructure and process controls to achieve more stringent product specifications and customer requirements. Products manufactured at NEB’s Rowley facility are manufactured in compliance with ISO 9001 and ISO 13485 quality management system standards. However, at this time, NEB does not manufacture or sell products known as Active Pharmaceutical Ingredients (APIs), nor does NEB manufacture its products in compliance with all of the Current Good Manufacturing Practice regulations. Q: Can you tell me more about the switch from BSA to Recombinant Albumin (rAlbumin) in NEBuffers? A: NEB is excited to announce that we have switched BSA-containing reaction buffers (NEBuffer 1.1, 2.1, 3.1 and CutSmart® Buffer) to Recombinant Albumin-containing buffers (NEBuffer r1.1, r2.1, r3.1 and rCutSmart™ Buffer). We are also in the process of moving all restriction enzyme formulations to contain rAlbumin. We feel that moving away from animal-containing products is a step in the right direction and are able to offer this enhancement at the same price.