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Addgene Expands Repository with Fire Vector Kit; Plans More RNAi Plasmids


Addgene, a new non-profit organization establishing a centralized repository of plasmids for scientists, announced this week the availability of a kit containing 288 vectors deposited by Stanford University researcher and RNAi pioneer Andrew Fire.

If Addgene can navigate the choppy waters of university technology transfer, it expects to have many more RNAi-related plasmids available soon.

The idea for Addgene grew out of the frustrations of co-founder Melina Fan, who received her PhD in cell biology from Harvard University. While conducting her graduate work, "I did a screen, and was looking for a whole bunch of different proteins," she told RNAi News this week. "I wrote to many people to get plasmids, and some of [those people] couldn't find them and some just didn't respond. So the idea [for the repository] was born there."

The goal of Addgene is to facilitate "academic-to-academic plasmid transfer, because there was a growing need in the community for such an organization," she said. "Analogous repositories exist for cell lines, such as [the American Type Culture Collection], or for mouse strains, such as the Jackson Laboratory, but there really is no central place for plasmids."

Besides having to deal with contacting numerous labs to obtain needed vectors, a researcher can face added difficulties given the turnover common to labs, Fan said. "Because of the nature of the training process, people are only in the labs for about five years, and sometimes less. And what happens is that their plasmids get lost, or the information on how the plasmid was created gets lost. [Addgene] will help prevent that."

To move her idea forward, Fan enlisted the aid of fellow Harvard graduates Sharon Ou, who is Addgene's director of biology, and Judy Tsai, who is the organization's European liaison. Additionally, Addgene brought on Benjie Chen, a recent PhD graduate in computer science from MIT, who handles the group's website design and laboratory information-management systems.

Organizational and financial expertise was found in Fan's brother, Kenneth Fan, who holds a bachelor's degree in computer engineering from Tufts University and most recently spent time as a financial analyst for Credit Suisse First Boston.

Though less than a year old, Addgene appears to be off to a good start. The organization has secured financing from a group of undisclosed donors, and is operating in a Cambridge, Mass., space sub-leased from Harvard at a reduced rate. Additionally, Addgene has assembled a group of scientific advisors that includes Harvard Medical School professors Bruce Spiegelman and Constance Cepko, and Yale University professor and Cell Biology editor-in-chief Ira Mellman.

According to Fan, Addgene's current plasmid collection includes deposits made by researchers from the Whitehead Institute, Harvard, MIT, and now Stanford with Fire's kit.

"We're going university by university" to seek plasmid donations from labs, Fan said. "I happened to be in California and e-mailed [Fire]. He wrote back and was very excited to work with us because shipping out 300 plasmids was a lot of work."

The 288 vectors in the Fire kit include lacZ and GFP fusion vectors for C. elegans; vectors for tagging C. elegans exons and introns with GFP; control plasmids for RNAi; vectors for bacterial-mediated RNAi; hairpin sequences used to test promoters for their ability to trigger RNAi; vectors for Smg-dependent expression; and vectors for localization of expressed proteins to nucleoli and plasma membrane, Addgene states on its website. The vectors are divided into three 96-well plates.

Generally, Addgene sells individual plasmids for $65 each if one to five are ordered. That price falls to $55 per plasmid if between six and 20 are ordered, and $45 per plasmid if 21 or more are purchased.

However, "for scientists that don't want people to pay $65 for their plasmids, they can pay a $30 upfront fee which covers the cost of sequencing," Fan said. Fire has done so, and so Addgene is selling his plasmids for $40 apiece. The entire Fire kit costs $375.

Fan stressed that "one of the advantages of getting constructs from Addgene is that they've been tested and the data has been published. All of that article information is linked from the plasmid information page [on the organization's website]. So the scientist will really be using tools that have been used before and will have data available to them," she said.

The Fire plasmids make up the first RNAi collection available through Addgene's website right now, Fan noted. "Although we have more RNAi plasmids in our repository right now, we can't actually put them online until we've signed an agreement with the university that deposited them."

Currently, material transfer agreements are handled through the mail or via fax, Fan said. However, the organization is in the process of establishing an electronic system through which "the person requesting [plasmids] clicks 'I agree,' and their tech transfer office also logs [onto our system] and clicks 'I agree.'" According to Kenneth Fan, "we're still going to have all the documentation that's normally done, it's just going to be electronic — but that's after we sign an initial depository agreement to allow scientists from a certain institution to deposit with us."

Once this is completed, Melina Fan said, "it will be much faster to do the MTA process. So, we're anticipating that several RNAi vectors are going to come online soon. Some of them are targeted against various genes, but we're also expecting an empty lentiviral RNAi vector [for mammalian expression] to come on soon," she said.

Currently, Addgene is focused only on academic-to-academic plasmid transfer, Kenneth Fan said. "But one option we do allow institutions is to bank material with us, and then … if they want to negotiate with a company [on their own] to distribute that material, they can send us a [notice] saying that they've negotiated with the company" and Addgene will send off the material.

"We're not aiming for that, but it will be an option," he added.

— DM

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