By Shadia Nasralla
VIENNA (Reuters) - Austrian forensics experts who helped solve the mystery of Russia's murdered imperial family could soon shed light on the apparent massacre of 43 Mexican students through analysis of the tiniest of DNA fragments from badly burnt remains.
The bodies of students abducted by corrupt police in Mexico six weeks ago were apparently burnt to ashes by drug gang members in an attempt to destroy the evidence.
Mexican authorities have said they would send the remains to Innsbruck's Medical University for DNA identification.
Officials at the forensics institute at Innsbruck Medical University are not allowed to confirm they are handling the Mexican investigation.
Generally speaking, DNA analysis of remains reduced to ashes would be very difficult, said molecular biologist Walther Parson, a leading expert at the institute.
But he expressed confidence in the methods used by the institute in past cases, including that of the Russian Romanovs, whose bodies were more than a century old, had been doused in acid and partially burnt.
"We have to extract DNA (deoxyribonucleic acid) equivalent to only a few cells from a sample, no matter how big it is or what its biological condition is," Parson told Reuters.
All that is needed is around 66 picograms of DNA. One picogram is 10 to the power of minus twelve of a gram. Effectively a bit of dandruff, the root of a hair or a piece of bone or tooth can be enough to deliver useful results within weeks, Parson told Reuters in a telephone interview.
Mexico's Attorney General Jesus Murillo said the bodies were burnt at 1,600 Celsius (2,900 Fahrenheit), making it very difficult to identify the remains. Investigators found only two bone fragments, including a knee joint, that could yield DNA evidence.
If the Austrians isolated DNA from the remains, Murillo said in a television interview, further analysis would be needed in a laboratory in Spain.
The Austrian lab won international fame by reconstructing DNA profiles of victims of a 2004 tsunami in South Asia, whose bodies had been rotting in extreme heat and humidity.
In 2008, Innsbruck discredited claims of alleged direct descendents of the Czars by proving that all the Romanov children were killed with their parents after the Russian revolution.
Testing in both cases was led by Parson, one of around 30 DNA experts at the institute. The institute says it has one of Europe's biggest DNA data banks and has helped to solve more than 8,000 crimes.
"We don't use magic machinery ... The ways we use the instruments in our institute are particularly well executed and optimised," he said. "We can deal calmly and in a level-headed way with cases, even when there is huge media attention."
(Additional reporting by Dave Graham in Mexico City; Editing by Giles Elgood)