I recently had the opportunity to take advantage of a fabulous web-based resource called The Mammalian Gene Collection (http://mgc.nci.nih.gov/). In simplest terms, the MGC is a searchable collection of thousands of full-length open reading frame cDNA clones from human, rat, and mouse. Two very important points about the collection are: 1) the MGC is a physical, as opposed to a digital, collection of clones; and 2) the clones in the collection are available to the research community through the clone distribution network of the I.M.A.G.E. (Integrated Molecular Analysis of Genomes and their Expression) Consortium. The Consortium exists to “share high-quality, arrayed cDNA libraries and place sequence, map, and expression data on the clones in these arrays into the public domain.” In other words, when your research requires a specific cDNA clone for recombinant protein expression, mutation research, or the like, you no longer need to perform an initial literature search to find sources for potential clones.
From the MGC homepage, you first search (by keyword, gene symbol, or BLASTing a nucleotide sequence against the full-length MGC sequences) to see if your gene is a member of the collection. If it is, you are able to search and find the clone along with direct links to NCBI matches. Subsequent links provide detailed information on the library of origin and access to the MGC clone page (which has links to LocusLink, UniGene, and CGAP databases). After just a few minutes of following these links, you will have accumulated sufficient information to decide if it matches with the clone you are seeking. If you decide to purchase it, the process couldn’t be any easier.
On the left side of any of the MGC web pages is a link entitled “Where to buy.” Clicking on this link takes you to a page with links to 3 USA distributors and 2 European distributors. The distributor sites enable you to search for your clone via one of several unique identifiers (accession number, gene symbol, MGC number etc.). Once the clone is identified in the distributor database, you can then purchase it. Within a few days you will receive a frozen glycerol stock of E. coli containing your clone.
My personal experience with purchasing MGC clones is limited to Invitrogen, one of the 3 USA vendors. The Invitrogen site was very easy to navigate and the entire process was very smooth. The cost of the clone I purchased was $135. If you consider that nothing more than a few minutes time on the web is required to get one’s hands on a full-length clone, this is without a doubt a fair price. However, you might want to check the other distributor sites as well before purchasing as prices may vary. Invitrogen also offers sequence-verified clones in a Gateway expression vector to enable transfer of genes into a variety of expression systems. These ‘Ultimate ORF Clones’ clones are much more convenient to manipulate and the increased convenience is matched by an increase in price. The one I looked up was $750.
The MGC is a very well-planned and extremely helpful resource. Navigating is intuitive and the entire process, from searching for a specific clone to its purchase, is seamless. The amount of research time and resources that can be saved by taking advantage of what the MGC has to offer is staggering. I highly recommend it. For more information, see PNAS 99(26):16899-903, 2002, Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences.
Michael Campa, Ph.D.
Asst. Research Professor of Radiology
Duke University Medical Center