Scientists have not found any trace of native microbes in the first analysis of ice water from Lake Vostok in Antarctica.

Researchers analyzed the ice that froze on the drill bit while drilling the isolated lake in February this year. They revealed that the uppermost layer of Lake Vostok appears to be "lifeless," a report in Nature said.

Sergey Bulat of Petersburg Nuclear Physics Institute (Russia) and his research team counted the microbes and performed a DNA analysis to find out their phylotypes. They noticed that the three of the four microbes on the drill bit match the contaminants from the drilling oil.

The fourth one is not known, but scientists believe that it is mostly from the lubricant. The results of the analysis were presented at the 12th European Workshop on Astrobiology (ENEA 2012), in Stockholm, Sweden.

John Priscu, an American Antarctica researcher, told USNews it is not surprising that the Russians have not found microbial life in the lake.

"It's based on ice found on their drill, so it's a very contaminated sample. Secondly, when you take liquid water and freeze it, there's a partitioning-99 percent of the impurities, including microorganisms, are not being incorporated into the ice," he told USNews.

"The verdict is still out. We really need to go into the lake and sample it properly with sterile instruments," he said.

In February, Russian scientists successfully drilled to reach Vostok, a subglacial Antarctic lake that is buried and remains untouched for about 20 million years.

The Russian team will continue drilling later this year in December-January after weather forced them to stop drilling earlier in February. Bulat and his team hope that they could find microorganisms from the lower depths of the lake. But they will have to wait until next May (2013) to get clean samples, reported Nature.

Experts believe that microbes could possibly thrive in lakes using different sources of chemical energy even if sunlight doesn't penetrate. Finding microbial life could shed light on organisms that thrive in extreme environments on other planets.