To access your account, log in or register.	shopping cart | log in

FAQs for EcoRI Methyltransferase FAQs for DNA Modifying Enzymes and Cloning Technical Reference for DNA Modifying Enzymes and Cloning Enzyme Finder NEBcutter NEBuffer Chart Double Digest Finder Isoschizomers DNA Sequences and Maps REBASE EcoRI Methyltransferase Reaction Buffer S-adenosylmethionine (SAM)

Home > Products > DNA Modifying Enzymes and Cloning > Methyltransferases > EcoRI Methyltransferase EcoRI Methyltransferase Catalog # Size Concentration Price Qty   M0211L 50,000 units 40,000 units/ml $212.00 M0211S 10,000 units 40,000 units/ml $53.00 Prices are in US dollars and valid only for US orders. Download: MSDS PDF Methylation Site: Description: EcoRI Methyltransferase modifies the internal adenine residue (N6) of the sequence GAATTC. Source: An E. coli. strain that carries the cloned EcoRI modification gene from Escherichia coli RY13 (R. N. Yoshimori) Reagents Supplied: EcoRI Methyltransferase Reaction Buffer (10X) S-adenosylmethionine (SAM) Enzyme Properties Molecular Weight: Theoretical: 37,911 daltons Reaction & Storage Conditions Reaction Conditions: 1X EcoRI Methyltransferase Reaction Buffer Supplemented with 80 μM S-adenosylmethionine (SAM) Incubate at 37°C. 1X EcoRI Methyltransferase Reaction Buffer: 50 mM Tris-HCl 50 mM NaCl 10 mM EDTA pH 8.0 @ 25°C Unit Definition: One unit is defined as the amount of enzyme required to protect 1 μg λ DNA in 1 hour at 37°C in a total reaction volume of 10 μl against cleavage by EcoRI restriction endonuclease. Protection Assay Conditions: EcoRI Methyltransferase is incubated with 1 µg of λ DNA in 10 µl 1X EcoRI Methyltransferase Buffer, supplemented with 80 µM S-adenosylmethionine, for one hour at 37°C followed by 15 minutes at 65°C. The extent of protection by EcoRI Methyltransferase is determined by the addition of 40 µl NEBuffer 2 and 5 units of EcoRI restriction endonuclease. Incubation at 37°C for 30 minutes is followed by analysis on an agarose gel. Concentration: 40,000 units/ml Storage Conditions: 100 mM KPO4 200 mM NaCl 10 mM 2-Mercaptoethanol 0.1 mM EDTA 200 µg/ml BSA 50% Glycerol pH 7.4 @ 25°C Storage Temperature: -20°C Notes General notes: Storage of SAM: S-adenosylmethionine is stored at –20°C as 32 mM solution dissolved in sulfuric acid (0.005 M) and 10% ethanol. SAM in this solution stored under ideal conditions remains active for up to 6 months. SAM is unstable at (pH 7.5), 37°C, and should be replenished for reactions incubated longer than 4 hours. Many problems in achieving complete digestion can be alleviated by using fresh SAM. EcoRI Methyltransferase is inhibited by MgCl2. Only 50% activity is retained at a concentration of 4 mM MgCl2. FAQs Is S-adenosylmethionine (SAM) supplied with the Methyltransferase? What should be considered if the methylation is not going to completion? Can EcoRI Methyltransferase be heat inactivated? Does EcoRI Methyltransferase require MgCl2? Will EcoRI methylation block the ApoI restriction enzyme? Quality Control for Current Lot Quality control values for a specific lot can be found on the datacard which accompanies each product. 16-Hour Incubation:: Incubation of 1,500 units of EcoRI Methyltransferase with 1 μg of HindIII-digested λ DNA in 50 μl of 1X NEBuffer 2 for 16 hours at 37°C resulted in no detectable endonuclease degradation. Exonuclease Activity:: Incubation of 4,000 units of EcoRI Methyltransferase with 1 μg sonicated 3H DNA (105 cpm/μg) for 4 hours at 37°C in 50 μl NEBuffer 2 released < 0.3% of the total radioactivity. References Hoffman, J.L. (1986) Biochemistry, 25, 4444-4449. Reagents Sold Separately EcoRI Methyltransferase Reaction Buffer S-adenosylmethionine (SAM)