Processing samples (IMAGE) Northwestern University Caption Matthew Selensky processes water samples in the lab. He uses a vacuum system powered by a bicycle pump to draw the water through sterile filters, collecting the micro-organisms on the filter, which are preserved for later gene sequencing. Credit Natalie Gibb/Under the Jungle Usage Restrictions add credit License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.