How can NanoSIMS be used to determine which Roseobacters most strongly use DMSP as a sulfur source ...

 NanoSIMS is a highly sensitive technique that can be combined with other methods to quantify the relative proportions of isotopic atoms such as 34S incorporated into various isolated organisms from 34S~DMSP exposure. The organisms containing the highest 34S are likely those that assimilate DMSP the most. In NanoSIMS, a high-energy ion beam is directed onto a sample to break apart most chemical bonds such that secondary ions released represent the composition of the sample. The various secondary ions are quantified with a mass spectrometer.