Test Tubes (IMAGE) University of Washington Caption In the Seattle lab, the team cultured 36 species of marine microbes and then tested their ability to produce sulfonates. Each phytoplankton type has its own unique set of pigments that absorb and reflect different wavelengths of light, creating the range of colors in the test tubes. Credit Bryndan Durham/University of Washington Usage Restrictions With credit 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.