Aspirate the supernatant of the concentrated water sample to the total resuspended concentrate volume already determined. Do not aspirate below 5 mL for samples with small packed pellets. Perform this carefully and consistently to reduce the loss of organisms. The techniques listed below apply to aspiration in a 50-mL, 250-mL, or 500-mL centrifuge tube/bottle.
Reducing the vacuum pressure when aspirating below 30 mL may reduce loss of organisms.
View the videos demonstrating correct and incorrect aspiration; listen to the difference.