Rachel Rachid, Camila Wendt, Wanderley de Souza, Kildare Miranda
{"title":"Optimisation of freeze substitution protocols for the examination of malaria parasite structure by volumetric electron microscopy.","authors":"Rachel Rachid, Camila Wendt, Wanderley de Souza, Kildare Miranda","doi":"10.1111/jmi.70007","DOIUrl":null,"url":null,"abstract":"<p><p>Malaria is one of the deadliest infectious diseases in the world, annually responsible for over 400,000 deaths. It is caused by parasites of the genus Plasmodium, which undergo remarkable structural changes during their development within different cells across various hosts. An important approach to understand the structural basis of biochemical and physiological processes during Plasmodium infection has been the quantitative measurement of dimensional parameters obtained by different microscopy techniques. In this regard, sample preparation, particularly electron microscopy protocols that rely on room-temperature chemical fixation, has posed significant challenges, as it is known to produce artefacts such as shrinking, swelling and displacement of structures and osmolytes. In contrast, specimen immobilisation by cryofixation followed by freeze substitution minimises these artefacts and provides better sample preservation. Nevertheless, the composition of the freeze substitution medium may vary depending on the cell type, making it a critical factor for achieving optimal sample preparation. In this work, we optimised a freeze substitution protocol for the structural analysis of intraerythrocytic stages of the murine malaria models Plasmodium chabaudi and P. berghei. We tested different freeze substitution recipes, considering the biochemical composition of malaria membranes, and compared the results with those obtained through conventional chemical fixation. Overall, the results showed a significant improvement on the preservation of cell morphology and haemozoin crystals. Establishing an efficient and reproducible freeze substitution protocol for murine malaria models provides an important tool for advancing our understanding of the structural organisation of Plasmodium spp.</p>","PeriodicalId":16484,"journal":{"name":"Journal of microscopy","volume":" ","pages":""},"PeriodicalIF":1.9000,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of microscopy","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1111/jmi.70007","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MICROSCOPY","Score":null,"Total":0}
引用次数: 0
Abstract
Malaria is one of the deadliest infectious diseases in the world, annually responsible for over 400,000 deaths. It is caused by parasites of the genus Plasmodium, which undergo remarkable structural changes during their development within different cells across various hosts. An important approach to understand the structural basis of biochemical and physiological processes during Plasmodium infection has been the quantitative measurement of dimensional parameters obtained by different microscopy techniques. In this regard, sample preparation, particularly electron microscopy protocols that rely on room-temperature chemical fixation, has posed significant challenges, as it is known to produce artefacts such as shrinking, swelling and displacement of structures and osmolytes. In contrast, specimen immobilisation by cryofixation followed by freeze substitution minimises these artefacts and provides better sample preservation. Nevertheless, the composition of the freeze substitution medium may vary depending on the cell type, making it a critical factor for achieving optimal sample preparation. In this work, we optimised a freeze substitution protocol for the structural analysis of intraerythrocytic stages of the murine malaria models Plasmodium chabaudi and P. berghei. We tested different freeze substitution recipes, considering the biochemical composition of malaria membranes, and compared the results with those obtained through conventional chemical fixation. Overall, the results showed a significant improvement on the preservation of cell morphology and haemozoin crystals. Establishing an efficient and reproducible freeze substitution protocol for murine malaria models provides an important tool for advancing our understanding of the structural organisation of Plasmodium spp.
期刊介绍:
The Journal of Microscopy is the oldest journal dedicated to the science of microscopy and the only peer-reviewed publication of the Royal Microscopical Society. It publishes papers that report on the very latest developments in microscopy such as advances in microscopy techniques or novel areas of application. The Journal does not seek to publish routine applications of microscopy or specimen preparation even though the submission may otherwise have a high scientific merit.
The scope covers research in the physical and biological sciences and covers imaging methods using light, electrons, X-rays and other radiations as well as atomic force and near field techniques. Interdisciplinary research is welcome. Papers pertaining to microscopy are also welcomed on optical theory, spectroscopy, novel specimen preparation and manipulation methods and image recording, processing and analysis including dynamic analysis of living specimens.
Publication types include full papers, hot topic fast tracked communications and review articles. Authors considering submitting a review article should contact the editorial office first.