000278082 001__ 278082 000278082 005__ 20250501100249.0 000278082 0247_ $$2doi$$a10.21769/BioProtoc.5277 000278082 0247_ $$2pmid$$apmid:40291420 000278082 0247_ $$2pmc$$apmc:PMC12021588 000278082 037__ $$aDZNE-2025-00573 000278082 041__ $$aEnglish 000278082 082__ $$a570 000278082 1001_ $$0P:(DE-2719)9002412$$aAmaral, Mariana$$b0$$udzne 000278082 245__ $$aX-Ray Photon Correlation Spectroscopy, Microscopy, and Fluorescence Recovery After Photobleaching to Study Phase Separation and Liquid-to-Solid Transition of Prion Protein Condensates. 000278082 260__ $$aSunnyvale, CA$$bbio-protocol.org$$c2025 000278082 3367_ $$2DRIVER$$aarticle 000278082 3367_ $$2DataCite$$aOutput Types/Journal article 000278082 3367_ $$0PUB:(DE-HGF)16$$2PUB:(DE-HGF)$$aJournal Article$$bjournal$$mjournal$$s1746004932_5922 000278082 3367_ $$2BibTeX$$aARTICLE 000278082 3367_ $$2ORCID$$aJOURNAL_ARTICLE 000278082 3367_ $$00$$2EndNote$$aJournal Article 000278082 520__ $$aBiomolecular condensates are macromolecular assemblies constituted of proteins that possess intrinsically disordered regions and RNA-binding ability together with nucleic acids. These compartments formed via liquid-liquid phase separation (LLPS) provide spatiotemporal control of crucial cellular processes such as RNA metabolism. The liquid-like state is dynamic and reversible, containing highly diffusible molecules, whereas gel, glass, and solid phases might not be reversible due to the strong intermolecular crosslinks. Neurodegeneration-associated proteins such as the prion protein (PrP) and Tau form liquid-like condensates that transition to gel- or solid-like structures upon genetic mutations and/or persistent cellular stress. Mounting evidence suggests that progression to a less dynamic state underlies the formation of neurotoxic aggregates. Understanding the dynamics of proteins and biomolecules in condensates by measuring their movement in different timescales is indispensable to characterize their material state and assess the kinetics of LLPS. Herein, we describe protein expression in E. coli and purification of full-length mouse recombinant PrP, our in vitro experimental system. Then, we describe a systematic method to analyze the dynamics of protein condensates by X-ray photon correlation spectroscopy (XPCS). We also present fluorescence recovery after photobleaching (FRAP)-optimized protocols to characterize condensates, including in cells. Next, we detail strategies for using fluorescence microscopy to give insights into the folding state of proteins in condensates. Phase-separated systems display non-equilibrium behavior with length scales ranging from nanometers to microns and timescales from microseconds to minutes. XPCS experiments provide unique insights into biomolecular dynamics and condensate fluidity. Using the combination of the three strategies detailed herein enables robust characterization of the biophysical properties and the nature of protein phase-separated states. Key features • For FRAP in cells, we recommend using a spinning disk confocal microscope coupled with temperature and CO2 incubator. • For fluorescence microscopy, we recommend simultaneously imaging differential interference contrast (DIC) (or phase contrast) and fluorescence channels to obtain morphological details of phase-separated structures. • For XPCS, coherent X-ray beams, fast X-ray detectors in fourth and third synchrotron light sources, and X-ray free-electron lasers are required. 000278082 536__ $$0G:(DE-HGF)POF4-352$$a352 - Disease Mechanisms (POF4-352)$$cPOF4-352$$fPOF IV$$x0 000278082 588__ $$aDataset connected to CrossRef, PubMed, , Journals: pub.dzne.de 000278082 650_7 $$2Other$$aAmyloid dye 000278082 650_7 $$2Other$$aBiomolecular condensates 000278082 650_7 $$2Other$$aFluorescence microscopy 000278082 650_7 $$2Other$$aFluorescence recovery after photobleaching (FRAP) 000278082 650_7 $$2Other$$aLiquid-liquid phase separation (LLPS) 000278082 650_7 $$2Other$$aLiquid-to-solid transition 000278082 650_7 $$2Other$$aPhase transitions 000278082 650_7 $$2Other$$aX-ray photon correlation spectroscopy (XPCS) 000278082 7001_ $$aPassos, Aline R$$b1 000278082 7001_ $$0P:(DE-2719)9001599$$aMohapatra, Satabdee$$b2$$udzne 000278082 7001_ $$aFreire, Maria Heloisa$$b3 000278082 7001_ $$0P:(DE-2719)2812695$$aWegmann, Susanne$$b4$$udzne 000278082 7001_ $$aCordeiro, Yraima$$b5 000278082 773__ $$0PERI:(DE-600)2833269-6$$a10.21769/BioProtoc.5277$$gVol. 15, no. 8$$n8$$pe5277$$tBio-protocol$$v15$$x2331-8325$$y2025 000278082 8564_ $$uhttps://pub.dzne.de/record/278082/files/DZNE-2025-00573.pdf$$yOpenAccess 000278082 8564_ $$uhttps://pub.dzne.de/record/278082/files/DZNE-2025-00573.pdf?subformat=pdfa$$xpdfa$$yOpenAccess 000278082 909CO $$ooai:pub.dzne.de:278082$$popenaire$$popen_access$$pVDB$$pdriver$$pdnbdelivery 000278082 9101_ $$0I:(DE-HGF)0$$6P:(DE-2719)9002412$$aExternal Institute$$b0$$kExtern 000278082 9101_ $$0I:(DE-588)1065079516$$6P:(DE-2719)9001599$$aDeutsches Zentrum für Neurodegenerative Erkrankungen$$b2$$kDZNE 000278082 9101_ $$0I:(DE-588)1065079516$$6P:(DE-2719)2812695$$aDeutsches Zentrum für Neurodegenerative Erkrankungen$$b4$$kDZNE 000278082 9131_ $$0G:(DE-HGF)POF4-352$$1G:(DE-HGF)POF4-350$$2G:(DE-HGF)POF4-300$$3G:(DE-HGF)POF4$$4G:(DE-HGF)POF$$aDE-HGF$$bGesundheit$$lNeurodegenerative Diseases$$vDisease Mechanisms$$x0 000278082 9141_ $$y2025 000278082 915__ $$0StatID:(DE-HGF)0200$$2StatID$$aDBCoverage$$bSCOPUS$$d2024-12-17 000278082 915__ $$0StatID:(DE-HGF)0112$$2StatID$$aWoS$$bEmerging Sources Citation Index$$d2024-12-17 000278082 915__ $$0StatID:(DE-HGF)0100$$2StatID$$aJCR$$bBIO-PROTOCOL : 2022$$d2024-12-17 000278082 915__ $$0LIC:(DE-HGF)CCBYNC4$$2HGFVOC$$aCreative Commons Attribution-NonCommercial CC BY-NC 4.0 000278082 915__ $$0StatID:(DE-HGF)0501$$2StatID$$aDBCoverage$$bDOAJ Seal$$d2024-04-18T10:10:42Z 000278082 915__ $$0StatID:(DE-HGF)0500$$2StatID$$aDBCoverage$$bDOAJ$$d2024-04-18T10:10:42Z 000278082 915__ $$0StatID:(DE-HGF)0700$$2StatID$$aFees$$d2024-12-17 000278082 915__ $$0StatID:(DE-HGF)0150$$2StatID$$aDBCoverage$$bWeb of Science Core Collection$$d2024-12-17 000278082 915__ $$0StatID:(DE-HGF)9900$$2StatID$$aIF < 5$$d2024-12-17 000278082 915__ $$0StatID:(DE-HGF)0510$$2StatID$$aOpenAccess 000278082 915__ $$0StatID:(DE-HGF)0030$$2StatID$$aPeer Review$$bDOAJ : Peer review$$d2024-04-18T10:10:42Z 000278082 915__ $$0StatID:(DE-HGF)0561$$2StatID$$aArticle Processing Charges$$d2024-12-17 000278082 915__ $$0StatID:(DE-HGF)0300$$2StatID$$aDBCoverage$$bMedline$$d2024-12-17 000278082 915__ $$0StatID:(DE-HGF)0199$$2StatID$$aDBCoverage$$bClarivate Analytics Master Journal List$$d2024-12-17 000278082 9201_ $$0I:(DE-2719)1810006$$kAG Wegmann$$lProtein Actions in Neurodegeneration$$x0 000278082 980__ $$ajournal 000278082 980__ $$aVDB 000278082 980__ $$aUNRESTRICTED 000278082 980__ $$aI:(DE-2719)1810006 000278082 9801_ $$aFullTexts