D. BalasubramanianCh Mohan RaoB. PanijpanCentre for Cellular and Molecular Biology indiaMahidol University2018-10-122018-10-121984-01-01Science. Vol.223, No.4638 (1984), 828-830003680752-s2.0-0021347929https://repository.li.mahidol.ac.th/handle/123456789/30723Noninvasive photoacoustic spectroscopy was used to study the malaria parasites Plasmodium chabaudi and Plasmodium berghei, their pigment, and ferriprotoporphyrin IX, which is a by-product of the hemoglobin that the parasite ingests. The results indicate that the pigment consists of ferriprotophorphyrin self-aggregates and a noncovalent complex of ferriprotoporphyrin and protein. Spectra of chloroquine-treated parasites reveal in situ interaction between the drug and ferriprotoporphyrin. Chloroquine-resistant parasites, readily distinguishable by this method, appear to degrade hemoglobin only partially.Mahidol UniversityMultidisciplinaryArticleSCOPUS10.1126/science.6695185