Can Crusher-Culley Protocol
Using sterile technique, remove the plunger from the 60mL syringe.
Attach the 0.02 µm filter (Anotop) to the end of the syringe.
Pour 50 mL of 0.2 µm filtrate into the 60-mL syringe.
Replace plunger and mount the syringe and filter into the can crusher.
Push the 0.2 µm filtrate very slowly through the Anotop, using the can crusher and applying gentle, steady pressure.
Watch carefully for the last drop of water to go into the Anotop, and then stop pushing.
Using sterile technique, remove the Anotop from the syringe.
Do not touch the filter inlet or outlet.
Suck up the remaining 50mL of 0.2 µm filtrate for this depth into the 60-mL syringe.
Re-attach the Anotop to the end of the syringe.
Repeat Step 5: Push the 0.2 µm filtrate slowly through the Anotop, using the can crusher.
Remove the Anotop from the syringe.
Write on the Anotop itself using a waterproof Sharpie. 
Wrap the Anotop in clean parafilm, covering both the inlet and outlet.
Label a piece of aluminum foil with date, depth, and location (using waterproof Sharpie).
Wrap the parafilmed Anotop in the labeled aluminum foil.
Label a Ziploc bag with date, depths, and location.
Collect several Anotops to put into one labeled Ziploc: one location/sample site per bag.
Put the foil-wrapped Anotops into the labeled Ziploc bag.
Freeze the Ziploc in -80°C freezer (if no -80°C freezer is available, use a -20°C freezer).
Discard the syringe and filtrate (unless you need some sterile water).
