FabULOUS® (SpeB)

FabULOUS (SpeB) is a recombinantly produced cysteine protease that under reduced conditions digests in the hinge region of antibodies from many species and subclasses, including human, mouse, rat and goat.


FabULOUS is available in two product formats: as a lyophilized powder (FabULOUS Enzyme) and as a lyophilized powder in a kit together with affinity spin columns (FabULOUS Fab kit), for easy preparation and purification of Fab fragments from mouse IgG. 

Product Information

FabULOUS (SpeB) is an enzyme for digestion of IgG in the upper hinge region. All subclasses of human (except hIgG4), mouse, rat, goat and sheep IgG are digested by FabULOUS, yielding Fab and Fc fragments. The primary digestion site on human IgG1 is ..KTHT / CPPCPAPE.. and on mouse IgG1 ..KPCIC / TVPEVS..

The molecular weight of FabULOUS is 28 724 Da and the enzyme contains a His-tag.

FabULOUS Primary Digestion Site


Mouse IgG1 ..KPCIC / TVPEVS..

For more species please visit Applications to view the IgG protease digestion chart for more species and subclasses

Key Characteristics

  • Digestion of IgG in the hinge region
  • Active on IgG from many species, e.g. human, mouse, rat and goat
  • A rapid protocol – 1 hour digestion


  • A digestion chart of more species and subclasses is found under Application

Product Formats

FabULOUS® Enzyme

FabULOUS enzyme supplied as lyophilized powder. The enzyme is available in a 2000 unit vial (1 unit digests 1 ug IgG).

FabULOUS® Fab kit mouse

FabULOUS Fab kit mouse is used for rapid and easy preparation and purification of Fab fragments from mouse IgG. The kit consists of two parts; lyophilized FabULOUS enzyme and affinity spin columns for purification of intact Fab fragments.

Enzyme Reference Tool

We have developed an “Enzyme Reference Tool” that organizes all published papers 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


We have not found that FabULOUS (SpeB) digest human IgG4. For other subclasses and species tested please visit

Find all FAQ here

Patent and Disclaimer


All rights reserved. Aspects of FabULOUS technology are encompassed by pending patent applications in the name of Genovis AB.
The trademark FabULOUS is the property of Genovis AB. FabULOUS is duly registered in EU, China, Japan, Australia, Canada, South Korea and USA.
For research use only. Not intended for any animal or human therapeutic diagnostic use.
All goods and services are sold subject to Genovis’ General Terms and Conditions of Sale.
©2017 Genovis AB.