We prepared a sample by placing a 1 cm diameter ring of 1 mm thick vacuum grease on a 24 mm × 60 mm glass coverslip. We added 5 l of the oocyst suspension into the ring, after which we sealed it by placing a 23 mm × 23 mm glass coverslip on top. After the sample was placed in the LTRS instrument, we measured the Raman spectra using 2 accumulations of 10 seconds for spores and oocysts, and using 2 accumulation of 90 seconds for bacterial cells. We measured on 100 individual oocysts each for both viable and neutralized oocysts and averaged the spectra.