Figure F9. Scheme for inoculation of tubes for most probable number (MPN) counts of prokaryotes. Tubes were filled with 9 mL of sterile medium and were inoculated with either sediment slurry or directly with sediment using a 5-mL syringe with the Luer end removed. The tenfold dilutions were done through three to six steps, sufficient that the last dilutions would probably not contain growing prokaryotes. The tubes showing positive growth after several weeks to months of incubation at a specific temperature were recorded and used to calculate the most probable number of viable cells in the original sample (according to a statistical table). The highest dilutions showing growth were subsequently used as inoculum for new dilution series, with the ultimate purpose of bringing cells into pure culture.

Figure F9. Scheme for inoculation of tubes for most probable number (MPN) counts of prokaryotes. Tubes were filled with 9 mL of sterile medium and were inoculated with either sediment slurry or directly with sediment using a 5-mL syringe with the Luer end removed. The tenfold dilutions were done through three to six steps, sufficient that the last dilutions would probably not contain growing prokaryotes. The tubes showing positive growth after several weeks to months of incubation at a specific temperature were recorded and used to calculate the most probable number of viable cells in the original sample (according to a statistical table). The highest dilutions showing growth were subsequently used as inoculum for new dilution series, with the ultimate purpose of bringing cells into pure culture.