To trap oocysts and acquire Raman spectra we used our LTRS instrument that is custom-built in an inverted microscope (IX71, Olympus) , with the schematic of the system shown in Figure . We used a Gaussian laser beam operating at 785 nm (Cobolt 08-NLD) that is coupled into the microscope using a dichroic shortpass mirror with a cut-off wavelength of 650 nm (DMSP650, Thorlabs). Imaging and focusing of the beam was achieved by a 60× water immersion objective (UPlanSApo60xWIR, Olympus) with a numerical aperture of 1.2 and a working distance of 0.28 mm. The same laser was used for Raman light excitation. In general, we operated the laser at fixed output power of 100 mW corresponding to a power of about 60 mW in the sample (total energy of 1.2 J when exposed for 20 seconds).