Hu­man DNA safe after trip to space

The Star Early Edition - - NEWS -

WASH­ING­TON: DNA mol­e­cules at­tached to the out­side of a rocket may be able to sur­vive a trip to sub­or­bital space and back into the Earth’s at­mos­phere at ex­tremely high tem­per­a­tures, ac­cord­ing to a study re­leased yes­ter­day.

The ex­per­i­ment, car­ried out on the TEXUS -49 rocket mis­sion in March 2011, “showed that DNA could be re­cov­ered from all ap­pli­ca­tion sites on the ex­te­rior of the rocket”, ac­cord­ing to the study pub­lished in PLOS ONE jour­nal.

The sur­viv­ing mol­e­cules were still able to trans­fer ge­netic in­for­ma­tion to cells and bac­te­ria, even after ex­po­sure to tem­per­a­ture as high as 1 000ºC, ac­cord­ing to co-au­thors Cora Thiel and Oliver Ull­rich from the Univer­sity of Zurich.

The au­thors said the ex­per­i­ment could be the ba­sis for “a model for nu­cleic acids that could serve as biomark­ers in the search for past or present ex­trater­res­trial life”.

“DNA plays an im­por­tant role as a biomarker for the search of ex­trater­res­trial sig­na­tures of life, and sci­en­tists are work­ing to char­ac­terise and com­pare the in­flu­ence of Earth and space con­di­tions on DNA,” the study said.

Re­searchers at­tached ar­ti­fi­cial plas­mid DNA with a floures­cent marker to three dif­fer­ent spots on the rocket for the ex­per­i­ment, which was ini­tially de­signed to test for biomarker sta­bil­ity dur­ing space flight and re­turn to Earth.

Thiel and Ull­rich said they were “to­tally sur­prised” by the re­sults of the ex­per­i­ment, and did not think the mol­e­cules would sur­vive the jour­ney.

“We never ex­pected to re­cover so many in­tact and func­tional ac­tive DNA.”

The sci­en­tists say the re­sults raise con­cerns about con­tam­i­nat­ing space­crafts, lan­ders and land­ing sites with DNA from Earth.

“It is not only an is­sue from space to Earth, it is also an is­sue from Earth to space and to other plan­ets,” the coau­thors said. – Sapa-AFP

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