In Figure we show Raman spectra of these pathogens alongside the spectrum from C. parvum oocysts. We observe that the Raman spectra of the oocysts differ greatly from those of other non-oocyst pathogens. The most prominent Raman peaks of spore pathogens B. cereus and C. difficile occur at 1017 cm -1 in close conjunction with a smaller peak at 1001 cm -1 . These two peaks are characteristic peaks of CaDPA. Although these peaks are comparable in appearance to the sharp peak of the Cryptosporidium oocyst appearing at 1005 cm -1 , the oocysts are clearly distinguishable from the spore pathogens by their lack of prevalent Raman peaks at 660 and 825 cm -1 , as well as their significant activity between 1050 -1350 cm -1 . Comparing the Raman spectrum of the oocysts to those of V. cholerae and E. coli, we similarly observe prominent peaks around 1000 cm -1 . Unlike the spore pathogens but similarly to C. parvum, V. cholerae and E. coli exhibit active Raman spectra with several broad peaks around 1100 and 1250 cm -1 . The two can, however, be distinguished from C. parvum by their prevalent peak characteristic of DNA and situated around 780 cm -1 , which is largely obscured in the Raman spectrum of C. parvum. The Raman peaks of C. parvum are also significantly more intense in the 1200-1800 cm -1 , likely due to the larger amount of phospholipid compared to the cell.