FabRICATOR LE (Low Endotoxin)

FabRICATOR is a recombinantely modified IdeS protease from Streptocoocus pyogenes originally developed by Genovis for biotech applications requiring highest standard and consistency.

FabRCATOR LE is the IdeS enzyme for endotoxin sensitive assays.  This product formulation has extremely low levels of endotoxins per vial (<0.04 EU /vial for the 2000 Unit vials).

  • Precise - digest the IgG at one single site just below the hinge
  • Robust - works right out of the box every time. No need for optimization
  • Safe - no risk of over digestion 
  • Fast - 30 minute digestion protocol



FabRICATOR LE enzyme is supplied as lyophilized powder with no preservatives added and is available in two different pack sizes; 2000 and 5000 units. This product formulation has extremely low levels of endotoxins per vial: <0.04 EU /vial for the 2000 unit vials and <0.10 EU/vial for the 5000 unit vials.


Don't hesitate to contact us if you need a quotation or have inquiries on price of bulk quantities.

Detailed Information 

FabRICATOR LE digests IgG only at one specific site just below the hinge region, resulting in F(ab’)2and Fc-fragments. Since FabRICATOR LE only cleaves at one specific site below the hinge region, there is no risk of over digestion if the incubation time is increased for several hours. 

FabRICATOR LE digests IgG under physiological reaction conditions thus preserving the immunoreactivity. Best activity is obtained at 37°C but digestion can also be performed at room temperature using prolonged reaction time. 


FabRICATOR LE digests all subclasses of human, monkey, rabbit and sheep IgG. FabRICATOR has limited activity on mouse IgG2a and IgG3 and for digestion of mouse IgG2a and IgG3 the use of FabRICATOR Z is recommended.

Follow this link to view a protease IgG digestion chart with species 


The enzyme is reconstituted by addition of water and after reconstitution FabRICATOR LE is stable for 1 month at +4-8°C. The enzyme can be aliquoted and stored at -20°C for at least 6 months. The product is shipped at ambient temperature but should be stored at -20°C upon arrival.

Unit definition

One unit digests ≥ 95% of 1µg human IgG when incubated in 10 mM sodium phosphate, 137 mM NaCl, 2.7mM KCl pH 7.4 at 37°C for 30min.


Buffers tested for compatibility with FabRICATOR LE digestion at different pH. Note that FabRICATOR LE enzyme is irreversibly inactivated below pH 5.0. Digestion above pH 8.0 requires prolonged/optimized conditions.

  • Phosphate buffer saline (PBS) 6.0 – 8.0
  • Tris buffer 7.0 – 8.0
  • MES buffer 5.5 – 6.5
  • HEPES buffer 7.0 – 8.0
  • Ammonium bicarbonate buffer 6.0 – 7.0
  • Sodium acetate buffer 6.0



FabRICATOR in QC applications

FabRICATOR was described in a recent paper by Merck Research Laboratories for domain characterization of therapeutic antibody products. Here you can read more and download the complementary full paper.

mAb Quality in Cell Culture

Due to the extraordinary specificity and robustness of FabRICATOR and IgGZERO they are becoming a vital tool for the ever-increasing demand of analytical characterization of large complex biomolecules.

Find all applications here

Enzyme Reference Tool

FabRICATOR is used frequently for studying important quality attributes of antibody-based biotherapeutics. To help you find the reference of interest we developed an Enzyme Reference Tool that organizes all papers published using our products. With this tool you can filter by quality attribute, enzyme used, type of antibody molecule and technology.


Latest reference using this product

FAQ and Support

Latest FAQ

There should not be any problems to use low concentrations of IgG. If you don't get complete digestion, try to increase the incubation time. There is no risk of over digestion and the incubation time can be prolonged to over night if necessary.
An alternative would be to increase the ratio enzyme to antibody (i.e. Follow protocol for mouse IgG). We have not made any specific tests on low concentrations but we have not heard that it would be any problems.

Yes, FabRICATOR can cleave Fc-Fusion proteins. For example Enbrel is effectivelty cleaved by FabRICATOR into Fc and TNFR. Enbrel (etanercept) is a fusion protein composed of the Fc domain of hIgG1 and the p75 tumor necrosis factor receptor (TNFR).

FabRICATOR is very specific and small changes in the sequence (..CPAPELLGGPSVF..) may reduce or completely impair the ability to digest the IgG.

We have tested a few different modified sequences and we can see that the enzyme digest the IgG to some degree to Fab2 and Fc under somewhat modified reaction conditions. We then obtained a mixture of Fc, Fab2 and single cut mAb (one of the HC still undigested).

We used PBS buffer but with greatly reduced salt concentration (5-10 mM instead of 140 mM) which appeared to promote digestion. We also added 10X more enzyme than recommended amount and prolonged incubation time.

It is very difficult to predict the outcome for a specific modification. It might work, but we cannot guarantee it unfortunately.

Find all FAQ here

Patent and Disclaimer


Genovis AB hold a license for exclusive worldwide use of biotechnical industrial applications of IdeS covered by any patents derived from International publication WO03051914, including granted US Patent No US7666582.
Other aspects of FabRICATOR®technology are encompassed by pending patent applications in the name of Genovis AB.

The trademark FabRICATOR® is the property of Genovis AB.

For research use only. Not intended for any animal or human therapeutic diagnostic use.