Nitrogen Research (IMAGE) University of Kansas Caption Researchers from Kansas State University and the University of Kansas use liquid nitrogen to freeze a core of stream sediment collected from Kings Creek at Konza Prairie Biological Station. The core was sectioned and used to analyze genes of nitrogen cycling organisms from the stream sediment microbiome. The method is unofficially referred to as the 'popsicle method' because the copper tube is inserted into the sediment and liquid nitrogen poured into the tube to freeze the sediment in a shell around the tube. Credit Walter Dodds, Kansas State University Usage Restrictions None License Licensed 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.