stylized photo representing FastDigest restriction enzymes  

Thermo Scientific™ FastDigest™ enzymes are an advanced line of restriction enzymes that create a new standard in DNA digestion. During our 30 years of restriction enzyme research, we compiled one of the largest collections of restriction enzyme producing bacterial strains in the industry. Our large section of enzyme isoschizomers and state-of-the-art production facility facilitated the creation of the unique system of 176 FastDigest restriction enzymes.

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176 FastDigest enzymes available

Over the course of 30 years, our search for restriction enzymes led us to acquire one of the largest collections of restriction enzyme-producing bacterial strains in the industry. Our wide selection of isoschizomers and ability to produce enzymes of exceptional purity enabled us to create the unique system of 176 FastDigest restriction enzymes formulated to have 100% activity in a single buffer.

30 years of experience

  • >3000 restriction enzyme producing strains
  • >30% of all known enzymes discovered
  • >30% of all known enzymes cloned
  • 176 FastDigest enzymes available
  • FastDigest Green Buffer for direct loading on gels

The Great Double Digestion Day

  Old Standard
Conventional restriction enzymes
New Standard
FastDigest restriction enzymes
Buffer System Up to 20 Buffers One Universal Buffer
Double/Multiple Restriction Digestion Limited by buffer compatibility Any enzyme combination possible
Reaction Time 1 hour - overnight 5 - 15 minutes
Direct Loading On Gels No
Downstream Applications Partial compatibility
100% buffer compatibility
Star Activity Yes No
Activity Definintion 1 unit of enzyme hydrolyzes 1µg of lambda DNA in 60 minutes in an optimal buffer for an enzyme 1 µL of FastDigest enzyme cleaves1 µg of substrate DNA in 5 to 15 minutes in FastDigest buffer

100% activity in a single buffer

The FastDigest Green Buffer and FastDigest Buffer are proprietary digestion buffers which support 100% activity of all FastDigest restriction enzymes. This system allows for double and multiple digestions with any combination of enzymes. No sequential digestions or buffer changes are needed.

Five minute single, double and triple digestions in FastDigest Green Buffer

Five minute plasmid DNA digestions with:

  • Lane M: Thermo Scientific™ GeneRuler™ Express Ladder (#SM1553)
  • Lane 1: Control, undigested plasmid DNA
  • Lane 2: FastDigest EcoRI
  • Lane 3: FastDigest EcoRI and FastDigest KpnI
  • Lane 4: FastDigest EcoRI, FastDigest KpnI and FastDigest SmaI

100% buffer compatibility with downstream applications

DNA/RNA modifying enzymes, such as ligases, phosphatases, kinases and mesophilic DNA polymerases have 100% activity in FastDigest and FastDigest Green Buffer. Therefore, enzymes used in downstream applications can be directly added to the FastDigest reaction mix. No buffer changes or purification steps are needed.

DNA/RNA Modifying Enzyme Activity in FastDigest Green Buffer/FastDigest Buffer
DNA Polymerase I, E.coli 100%
Klenow Fragment 100%
Klenow Fragment, exo- 100%
T4 DNA Polymerase 100%
T7 DNA Polymerase 100%
T4 DNA Ligase* 75-100%
FastAP Thermosensitive Alkaline Phosphatase 100%
T4 Polynucleotide Kinase 100%

* 0.5 mM ATP is required for T4 DNA Ligase activity.

Complete digestion in 5-15 minutes

Double and multiple digestions in one buffer in 5-15 minutes:

  • Saves time and effort, increasing throughput.
  • Digestion times are provided for all types of DNA templates (plasmid DNA, PCR product, genomic DNA).
  • No overnight digestions are required for any template.
  • Star activity is eliminated due to short reaction times.
Conventional restriction enzymes
Sequential digestion
FastDigest restriction enzymes
One reaction mixture
Reaction setup for Apal
 ~2 min
Reaction set up with FastDigest ApaI and XhoI
~2 min
60 min
5 min
Reaction setup for Xhol
~2 min
60 min
>2 hours
 7 min

Direct loading on gels

As an added convenience we developed the FastDigest Green Buffer which offers the same performance as the colorless FastDigest Buffer but enables direct loading of the reaction mixture on gels. The 10X FastDigest Green Buffer includes a density reagent and two tracking dyes for direct loading. The blue dye migrates with 3-5 kb DNA fragments in a 1% agarose gel and has an excitation peak of 424 nm. The yellow dye migrates faster than 10 bp DNA fragments in a 1% agarose gel and has an excitation peak of 615 nm.

FastDigest Green Buffer

Reaction mixture containing FastDigest Green Buffer:

  • Lane 1: Loaded into gel well, before electrophoresis
  • Lane 2: Separated, after electrophoresis
  FastDigest Green Buffer

No star activity

FastDigest enzymes in combination with FastDigest (Green) Buffer are designed to eliminate star activity:

  • Short incubation time (5-15 min), no need for prolonged digestions.
  • Universal buffer with optimal pH and salt concentration for all enzymes.
  • Optimal enzyme and glycerol concentrations.

Conventional restriction enzymes may display star or "relaxed" activity due to prolonged incubation times, high enzyme and/or glycerol concentration, high pH values or low ionic strength. By addressing all these issues, FastDigest enzymes enable single, double and even triple digestion in 5 minutes without any signs of star activity.

FastDigest (Green) Buffer

Five minute single and double digestion of plasmid DNA with no signs of star activity

Five minute plasmid DNA digestions with:

  • Lane 1: FastDigest SmaI
  • Lane 2: FastDigest EcoRI
  • Lane 3: FastDigest SmaI and FastDigest EcoRI double digest
  • Lane M: GeneRuler 1 kb Plus DNA Ladder (#SM1333)
  • Lane C: Control, Undigested plasmid DNA