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FAQs for dam 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 dam Methyltransferase Reaction Buffer S-adenosylmethionine (SAM)

Home > Products > DNA Modifying Enzymes and Cloning > Methyltransferases > dam Methyltransferase dam Methyltransferase Catalog # Size Concentration Price Qty   M0222L 2,500 units 8,000 units/ml $244.00 M0222S 500 units 8,000 units/ml $61.00 Prices are in US dollars and valid only for US orders. Download: MSDS PDF Methylation Site: Description: dam Methyltransferase modifies the adenine residue (N6) of the sequence GATC. Source: A E. coli strain that carries plasmid pTP166 carrying the dam modification gene of E. coli Reagents Supplied: dam Methyltransferase Reaction Buffer (10X) S-adenosylmethionine (SAM) Reaction & Storage Conditions Reaction Conditions: 1X dam Methyltransferase Reaction Buffer Supplemented with 80 μM S-adenosylmethionine (SAM) Incubate at 37°C. 1X dam Methyltransferase Reaction Buffer: 50 mM Tris-HCl 5 mM 2-Mercaptoethanol 10 mM EDTA pH 7.5 @ 25°C Unit Definition: One unit is defined as the amount of enzyme required to protect 1 µg of λ DNA in 1 hour at 37°C in a total reaction volume of 10 µl against cleavage by MboI restriction endonuclease. Protection Assay Conditions: dam Methyltransferase is incubated with 1 µg of λ DNA in 10 µl of 1X dam Methyltransferase Buffer, supplemented with 80 µM S-adenosylmethionine, for 1 hour at 37°C followed by 15 minutes at 65°C. The extent of protection is determined by addition of 40 µl 1X NEBuffer 3 supplemented with 10 mM MgCl2 and 10 units of MboI restriction endonuclease. Incubation at 37°C for 1 hour is followed by analysis on an agarose gel. Concentration: 8,000 units/ml Storage Conditions: 50 mM Tris-HCl 50 mM KCl 1 mM Dithiothreitol 10 mM EDTA 200 µg/ml BSA 50% Glycerol pH 7.5 @ 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. FAQs Is S-adenosylmethionine (SAM) supplied with the Methyltransferase? What should be considered if the methylation is not going to completion? Can dam Methyltransferase be heat inactivated? Does dam Methyltransferase require MgCl2? Is dam Methyltransferase sensitive to salt? Will DpnI cleave dam methylated DNA? 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 60 units of dam 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 contamination. Exonuclease Activity:: Incubation of 120 units of dam Methyltransferase with 1 μg sonicated 3H DNA (105 cpm/μg) for 4 hours at 37°C in 50 μl NEBuffer 2 released < 0.1% of the total radioactivity. Reagents Sold Separately dam Methyltransferase Reaction Buffer S-adenosylmethionine (SAM)