Simple In-liquid Staining of Microbial Cells for Flow Cytometry Quantification of the Microbial Population in Marine Subseafloor Sediments

Microbial cell counting provides essential information for the study of abundance profiles and biogeochemical interactions with surrounding environments. However, it often requires labor-intensive time-consuming processes, particularly subseafloor sediment samples, in which non-cell particles are abundant. We developed a rapid straightforward method staining microbial intracellular DNA by SYBR Green I (SYBR-I) to enumerate cells flow cytometry (FCM). initially examined efficiency at various dye/sediment ratios (volume ratio SYBR-I/sediment [vSYBR/vSed]). Non-cell strongly preferentially adsorbed SYBR-I dye, resulting unsuccessful when an insufficient ( 106 cm-3). Samples low (<105 cm-3) still require separation. This modified allows us efficiently process perform samples depth few hundred meters below seafloor higher throughput capability scale up than procedures employing microscopy-based observations.