Infection of Biomphalaria glabrata snails with Schistosoma mansoni miracidia

Collect lungs from patent mice into 50ml Falcon tubes containing pre-warmed 37°C 1x DPBS

Remove lungs from PBS and place in large mortar or laboratory blender

Gently homogenise lung tissue

Place homogenised lung slurry into a flask (size of flask depends on how many lungs you have) and fill with diH₂O or aquarium water

Cover flask in aluminum foil and shine light horizontally across the opening of the flask for 1-2 hrs

Take a small aliquot of water from the top of the flask using a glass Pasteur pipette and place into a petri dish. Using a stereomicroscope, check for swimming miracidia

Under a microscope, collect 15 miracidia with a glass Pasteur pipette per well

Alternatively (but less preferred) estimate the number of miracidia by counting 12-5µl aliquots in a petri dish. After collecting (shaking the tube in between) and placing the aliquots in the petri dish add 5µl of Lugol to each drop (this kills and stains the miracidia)

Place individual 5-8mm snails into 24-well culture plates and cover snails completely with 1x aquarium water

Expose snails to miracidia for at least 3 hours (up to overnight)

After exposure, remove the snails carefully using featherweight forceps and put them in a new tank with food

Dilute miracidia so that one miracidium can easily be collected in ~3-5µl of water

Collected single miracidium using fresh 10µl pipette each collection and place in 24-well plate

After a plate is filled, check each well under a microscope to verify there is a single miracidium in each well

Place individual 5-8mm snails in the wells containing confirmed single miracidium and cover snails completely with 1x aquarium water

Leave the plate overnight (inside incubator or room at 28°C)

The following day, transfer the snails to a new tank with food