Our project uses 3 new technologies: chip-based synthesis of DNA[1], multiplex automated genome engineering (MAGE)[2][3], and lamba red recombination[4][5], along with more traditional bioinformatics.

Although the project is the first to utilize several key technologies in novel ways, these technologies were developed outside of Harvard iGEM. The multiplex automated genome engineering (MAGE) method was developed by Harris Wang et al[2]. The chip-based synthesis method that we used to synthesize oligos for our zinc finger pool was developed by Sri Kosuri et al[1], and the actual oligo synthesis was generously provided by Agilent Technologies, a sponsor of iGEM. Lambda red was originally developed by Yu et al[4].

We hope that future iGEM teams will also use these techniques in their own synthetic biology projects.

Bioinformatics

See our Design page for details on the computational aspects of our project technology.

Zinc Finger Binding Site Finder

Check out our Zinc Finger Binding Site Finder Tool. This tool was designed and used to search the human genome for the six target DNA sequences that we used to design our custom zinc finger arrays.

Chip-Based Synthesis

Using microchip synthesis (provided by Agilent Technologies), we have 55,000 potential zinc fingers (whose sequences were generated by Team Harvard's bioinformatics) to test. These fingers will then be tried against the DNA sequences we wish to bind.

• Original Paper: http://www.nature.com/nbt/journal/v28/n12/full/nbt.1716.html
• Our protocols for getting DNA pools off of the chip: https://2011.igem.org/Team:Harvard/Protocols#Chip_DNA_Extraction

MAGE

Multiplex automated genome engineering (MAGE) is a new method for large-scale programming and evolution of cells. MAGE simultaneously targets many locations on the chromosome, thus producing combinatorial genomic diversity.

• Original Paper: http://www.nature.com/nature/journal/v460/n7257/full/nature08187.html
• Our Protocols: https://2011.igem.org/Team:Harvard/Protocols#MAGE

Lambda Red Mediated Recombineering

Genes can be altered by recombination with linear DNA molecules. This requires a high internal DNA concentration, achievable by electroporation. The lambda red system allows efficient recombination between homologous sequences as short as 40 bp, which frees us of the need to provide long tracts of homology for recombination into the chromosome.

• Gene Knockouts and Exchanges by Linear Transformation: http://rothlab.ucdavis.edu/protocols/Lin.Transform.html
• Open Wet Ware Protocol: http://openwetware.org/wiki/Recombineering/Lambda_red-mediated_gene_replacement
• Our Protocol: https://2011.igem.org/Team:Harvard/Protocols#Lambda_Red

Gibson (Isothermal) Assembly

An isothermal, single-reaction method for assembling multiple overlapping DNA molecules by the concerted action of a 5′ exonuclease, a DNA polymerase and a DNA ligase.

• Original Paper: http://www.nature.com/nmeth/journal/v6/n5/full/nmeth.1318.html
• Protocol: http://www.nature.com/protocolexchange/protocols/554#/main
• Our Protocol: https://2011.igem.org/Team:Harvard/Protocols#Isothermal_assembly

References

1. Sriram Kosuri, Nikolai Eroshenko, Emily M LeProust, Michael Super, Jeffrey Way, Jin Billy Li, George M Church. (2010). Scalable gene synthesis by selective amplification of DNA pools from high-fidelity microchips. Nature Biotechnology, 28(12):1295-9. [http://www.nature.com/nbt/journal/v28/n12/full/nbt.1716.html]

2. Harris H. Wang, Farren J. Isaacs, Peter A. Carr, Zachary Z. Sun, George Xu, Craig R. Forest, George M. Church. Programming cells by multiplex genome engineering and accelerated evolution. (2009). Nature, 460(7257):894-8. [http://www.nature.com/nature/journal/v460/n7257/full/nature08187.html]

3. Isaacs FJ, Carr PA, Wang HH, Lajoie MJ, Sterling B, Kraal L, Tolonen AC, Gianoulis TA, Goodman DB, Reppas NB, Emig CJ, Bang D, Hwang SJ, Jewett MC, Jacobson JM, Church GM. (2011). Precise manipulation of chromosomes in vivo enables genome-wide codon replacement. Science, 333(6040):348-53. [http://www.sciencemag.org/content/333/6040/348.full]

4. Yu D., H. M. Ellis, et al. (2000). An efficient recombination system for chromosome engineering in Escherichia coli. Proceedings of the National Academy of Sciences of the United States of America 97(11): 5978-5983.[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC165854/]