Fixation of marine samples for flow cytometry sorting
Prefilter seawater sample onto 200 µm mesh. 
Add 1.5 mL of prefiltered seawater sample to a 2 mL cryotube. 
Add DMSO. 
Add Pluronic (facultative). 
Vortex. 
Wait 10 min. 
Flash freeze in liquid nitrogen tank
