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VRP-0124 Recombinant Cre-11R Protein $300

Recombinant Cre-11R Protein

Product Name: Recombinant Cre-11R Protein
Catalog #:  VRP-0124
Manufacture:  LD Biopharma, Inc.

Cre-Lox recombination is a specific type of site-specific recombination developed by Dr Brian Sauer. Cre-Lox recombination involves the targeting of a specific sequence of DNA and splicing it with the help of an enzyme called Cre recombinase. Cre recombinase, often abbreviated to Cre, is a type I topoisomerase from P1 bacteriophage that catalyzes site specific recombination of DNA between LoxP site. Cre does not require any energy cofactors and Cre-mediated recombination quickly reaches equilibrium between substrate and reaction products. To efficiently delivery Cre protein into target cells without using Cre DNA or expression plasmid, we have modified Cre protein with SV40 large T nuclei translocation signal (NTS) domain, then fusion with 11 arginine (11R) domain to create cell membrane penetrable recombinant Cre-11R protein, which could be directly incubated in medium to induce Cre-Lox recombination for target cells. To achieve a true function for intracellular delivery recombinant Cre-11R protein, this recombinant protein has to enter cell membrane, escape from endosome trapping, migrate into nuclei to form tetramer for perform site-specific recombination. Combined with 293-LoxP-eGFP cell line, recombinant Cre-11R protein provides an excellent protein delivery testing for monitoring intracellular delivery efficiency.

Full-length Cre gene was constructed with 29aa N-terminal T7 tag/His/TEV cleavage site tag and C-terminal 11R tag. This protein was expressed in E. coli and chromatographically purified. To achieve the best intracellular protein delivery efficiency, ProFectinTM (protein delivery reagent) reagent should be used in serum free medium for 30 min incubation.

Gene Symbol:  Cre 
Accession Number:  YP_006472
Species:  Bacteriophage P1
Package Size:  50 µg / Vial   
Composition: 0.5 mg/ml, sterile-filtered, in 20 mM pH 8.0 Tris-HCl Buffer, with 100 mM NaCl, 10 mM KCl, 1 mM DTT and 10% Glycerol.
Storage: In Liquid. Keep at -80°C for long term storage. Product is stable at 4 °C for at least 7 days.
Key Reference: James J. Cronica, et al. Protein delivery of functional protein into mammalian cells in vitro and in vivo using a supercharged protein. ACS Chem. Biol DOI: 10.1021/ cb1001153. June 14 (2010)
Hongyan Zhou, et al. Generation of induced pluripotent stem cells using recombinant protein. Cell Stem cell. Vol 4. Issue 5: 381-384 (2009)

1. Protein intracellular transduction for in vitro Cre-loxP recombination.

2. Negative control for 11R-Tag human transcription factor mediated cell differentiation assay in vitro.

Quality Control:

1. Purity: > 90% by SDS-PAGE.

2. Functional Assay: Mix 1µg Cre-11R protein with 2ul ProFectinTM (LD Biopharma, Inc. Catalog # R-2000) by following ProFectinTM manufacture suggested protocol, and incubate transfection mixture on 0.25 x106 293-LoxP-eGFP cell line / well (6 well plate) for 30 min in serum free medium, will achieve > 35% transduction efficiency. (Positive for GFP cells).

Note: More info about ProFectinTM reagents kit, could be found at

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