UBC un­veils DNA cleaner

New tool uses elec­tric­ity to sep­a­rate sam­ples from im­pu­ri­ties


A new tool that wipes dirt and con­tam­i­nants out of DNA sam­ples could rev­o­lu­tion­ize the way po­lice in­ves­ti­gate se­ri­ous crime and ter­ror­ism, and help re­searchers find the root of dis­ease.

The de­vice, de­vel­oped at the Uni­ver­sity of B.C. and now in some pow­er­ful hands, uses elec­tric­ity to sep­a­rate con­tam­i­nants from DNA sam­ples that once would have been un­us­able.

Early pro­to­types of the in­stru­ment, called Aurora, have been sold to a U.S. de­fence com­pany, the U.S. navy and Cana­dian uni­ver­si­ties.

“There’s an enor­mous bot­tle­neck right now in DNA ex­trac­tion and anal­y­sis,” said An­dre Marziali, di­rec­tor of UBC’s en­gi­neer­ing physics depart­ment and Bo­real Ge­nomics, who led a re­search team in the cre­ation of the tool.

“I’ve been to con­fer­ences re­cently where there have been talks from FBI and CIA mem­bers who point to DNA ex­trac­tion as the tough­est part of the [in­ves­tiga­tive] process.”

Too of­ten, in­ves­ti­ga­tors are faced with large sam­ples of ev­i­dence, but the DNA is too mi­nus­cule or drown­ing in dirt and mol­e­cules that in­trude on its pu­rity, ren­der­ing it worth­less for foren­sic or health re­search.

One U. K. study found that one-third of all foren­sic case work failed be­cause DNA sam­ples were un­us­able, he said.

The re­search team, which in­cludes sci­en­tists from UBC and BC Can­cer Agency’s Genome Sci­ence Cen­tre, pub­lished its find­ings in the sci­en­tific jour­nal Pro­ceed­ings of the Na­tional Academy of Sci­ence.

On po­lice thrillers such as CSI, the bad guy leaves a cof­fee cup or a cig­a­rette butt be­hind, and the case is closed.

In re­al­ity, DNA sam­ples are of­ten ru­ined by tis­sue dyes, ground soil, dust, smoke and other small par­ti­cles.

The team used physics rather than chem­istry to sep­a­rate a DNA sam­ple from its dirt, Marziali said.

Work­ing with Aurora is sim­ple enough: A re­searcher places the sam­ple in­side the ma­chine, which “looks like a big white bread box.”

Within two hours, an elec­tric charge has sep­a­rated pure DNA from the “dirt” that sur­rounds it.

DNA re­sponds dif­fer­ently to elec­tri­cal charges than other mol­e­cules do, so the elec­tric­ity sep­a­rates the DNA from the mol­e­cules that sci­en­tists don’t need, Marziali said.

“Some [re­searchers] have used chem­i­cals which have the same prop­er­ties as DNA, so we’ve used physics where oth­ers have used chem­istry.”

Tests us­ing Aurora have so far proven suc­cess­ful.

When RCMP of­fered Marziali blue jeans stained with blood, Aurora was able to sep­a­rate the jeans’ indigo dye from the DNA and pull out a pure DNA sam­ple.

Used on or­gan­isms grow­ing in the Al­berta oil­sands, the de­vice showed how bac­te­ria have evolved in the soil.

Marziali said it could be use­ful for clin­i­cal re­search, to de­tect HIV or tar­get tu­mour mark­ers — “any case where you have a nee­dle in a haystack prob­lem.”

It could be used to in­ves­ti­gate bac­te­ria in soil or de­tect lis­te­ria, E.coli or other con­tam­i­nants in food, he said.

Iso­lat­ing DNA from dense dust and other par­ti­cles could also help re­searchers iden­tify an­cient skele­tons and de­tect danger­ous sub­stances such as an­thrax in the air in pub­lic places like sub­way sta­tions.

At $50,000 each, pro­to­types have been sold to the U.S. navy, a U.S. de­fence con­trac­tor, the BC Can­cer Agency, the Uni­ver­sity of Water­loo and McGill Uni­ver­sity in Montreal.

Lo­cally, it has gone from the bio­physics depart­ment to the uni­ver­sity’s bureau of le­gal den­tistry lab­o­ra­tory, where more re­search could help make it an everyday tool for foren­sics in­ves­ti­ga­tors.


UBC sci­en­tist An­dre Marziali headed a team that found a way to sep­a­rate DNA from im­pu­ri­ties for foren­sic anal­y­sis.

Newspapers in English

Newspapers from Canada

© PressReader. All rights reserved.