Deployment of the natural magnifier CMTKG for naked expansion microscopy of biological tissues

Deployment of the natural magnifier CMTKG for naked expansion microscopy of biological tissues | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Deployment of the natural magnifier CMTKG for naked expansion microscopy of biological tissues Bi-Chang Chen, Xuejiao Tian, Yi-Fen Cheng, Min-Ju Tsai, Tzu-Yang Lin, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3985326/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Expansion Microscopy (ExM) enhances biological imaging to the nanoscale level by enlarging biological specimens, increasing the separation between biomolecules while maintaining their spatial arrangement. By integrating ExM with traditional microscopy, super-resolution volumetric images can be captured efficiently without compromising tissue integrity. Accordingly, fine molecular structures previously indiscernible by means of standard fluorescence microscopy can be visualized. However, one of the major challenges with ExM is that the samples are embedded in the polymerized gel, which limits the use of high numerical aperture objective lenses due to their short working distances. To address this issue, we have developed an approach using carboxymethyl tamarind kernel gum (CMTKG) cross-linked with sodium acrylate to create a superabsorbent hydrogel suitable for ExM. This technique facilitates removal of excess polymers from the expanded sample, resulting in sample exposure to the objective lens. Here, we demonstrate that it is possible to achieve approximately 7X expansion of Drosophila melanogaster brains, free from surrounding hydrogel, in a process we have named Naked-ExM. Followed by iterative expansion, the centimeter-sized fly brain is obtained and the ~15 um sized synapses are measured at 15X expansion. Biological sciences/Neuroscience Physical sciences/Materials science expansion microscopy (ExM) Naked-ExM carboxymethyl tamarind kernel gum (CMTKG) Drosophila melanogaster brain 3D super-resolution imaging iterative ExM expanded synapse Full Text Additional Declarations There is NO Competing Interest. Supplementary Files NakedExMSupportingInformation20240320.pdf supplemetarymovie1.avi Supplement movie 1 supplementarymovie2.avi Supplement movie 2 Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3985326","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":291492636,"identity":"2091f607-f3fd-4a0b-9f67-d446420b1a16","order_by":0,"name":"Bi-Chang 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