A team from CEITEC Masaryk University (MUNI) in collaboration with researchers from two research institutes in Norway has, for the first time, captured how echovirus 18, a member of the enterovirus genus, releases its genetic material into cells to initiate infection. The study provides a structural view of an early stage of viral infection under near-native conditions. Using cryo-electron microscopy, the researchers discovered that the virus does not release its RNA through a small pore in its capsid, as had long been assumed. Instead, its protein shell partially disassembles, creating a large opening through which the viral genetic material escapes into the host cell. A detailed understanding of this genome release mechanism could eventually help develop compounds preventing enteroviruses from infecting cells.Enteroviruses are common human pathogens causing diseases ranging from the common cold and gastrointestinal infections to severe neurological disorders. Echovirus 18, the virus investigated in this study, is known primarily as a cause of meningitis and encephalitis in children. It belongs to the picornaviruses, a family of small, non-enveloped viruses whose genetic material is protected by a protein shell, the capsid, organized with icosahedral symmetry.To replicate within a cell, the enteroviruses must release their RNA – the molecule that carries viral genetic information – from the capsid, into the cell cytoplasm. Although this step is crucial for initiating infection, it has never been observed in infected cells.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/CEITEC_Vedci_z_CEITEC_jako_prvni_zachytili_jak_enteroviry_spousteji_infekci_bunek_71d553bb0e.jpg" alt="CEITEC/Plevka Lab: CEITEC Scientists Are the First to Capture How Enteroviruses Initiate Infection: View into a cell infected by echovirus 18. Echovirus 18 is shown in green and yellow, ribosomes in violet, and actin filaments in cyan. Scale 50 nm. " srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_CEITEC_Vedci_z_CEITEC_jako_prvni_zachytili_jak_enteroviry_spousteji_infekci_bunek_71d553bb0e.jpg 221w," sizes="100vw" width="1600" height="1128">“For a long time, two main theories existed about how picornaviruses deliver their RNA genomes into cells. One proposed that the genome leaves the capsid through a small opening. The other, supported by earlier work from our laboratory, suggested that the genome escapes from partially disassembled capsids missing pentamers of capsid proteins. However, both models were based on experiments with virus particles outside cells. We wanted to go one step further and see what really happens during infection inside a cell,” says <a target="_blank" rel="noopener noreferrer" href="https://www.ceitec.eu/liya-mukhamedova-ph-d/u89248?page=publication">Liya Mukhamedova</a>, the study’s first author from CEITEC MUNI.Using cryo-electron microscopy, which allows scientists to visualize biological structures at exceptionally high resolution, the researchers observed individual echovirus 18 particles directly within infected cells. They discovered that empty virus particles in infected cells lack parts of their capsids. It is through these openings that the virus releases its RNA.The study also revealed the role of the FcRn receptor, a cell-surface molecule that enteroviruses use to enter cells. The binding of the virus to the receptor triggers structural changes in the viral particle that prime it for subsequent genome release. The team showed that receptor binding causes the loss of the so-called pocket factor, a small molecule that normally helps stabilize the virus particle. The virus otherwise remains largely intact, suggesting that receptor binding is only the first step toward uncoating, while additional factors within the cell are required to complete the process and trigger genome release.“Infection is a complex process, during which enterovirus particles sense various interactions with cell components. The binding of echovirus 18 to the FcRn host-cell receptor triggers conformational changes in the virus, priming it for genome release.” – explains <a target="_blank" rel="noopener noreferrer" href="https://www.ceitec.eu/pavel-plevka-ph-d/u26854">Pavel Plevka</a>, head of the Structural Virology Research Group.The researchers did not observe the so-called activated particles that are key intermediates in the enterovirus uncoating process. This suggests that genome release in cells occurs much faster than previous experiments had suggested.By combining structural data obtained from studies of virus particles outside living cells with observations of infected cells, the study offers a picture of how enterovirus infection begins. Moving beyond simplified experiments with isolated virus particles, it brings scientists closer to understanding the earliest stages of enterovirus infection as they occur in living cells. The study, was published in the <a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1073/pnas.2601182123">PNAS journal</a>.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/CEITEC_Vedci_z_CEITEC_jako_prvni_zachytili_jak_enteroviry_spousteji_infekci_bunek_2_3601bf1df9.jpg" alt="CEITEC/Plevka Lab: CEITEC Scientists Are the First to Capture How Enteroviruses Initiate Infection: Reconstructions of E18 particles from infected cells. The particles are rainbow-colored based on the distance from the particle center. Scale 10 nm." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_CEITEC_Vedci_z_CEITEC_jako_prvni_zachytili_jak_enteroviry_spousteji_infekci_bunek_2_3601bf1df9.jpg 245w," sizes="100vw" width="1600" height="906"><blockquote><h4>Article</h4><h4><a target="_blank" rel="noopener noreferrer" href="https://www.pnas.org/doi/10.1073/pnas.2601182123">Particles of echovirus 18 open to release their genomes in vivo</a></h4>Liya Mukhamedova, David Buchta, Zuzana Trebichalská, Yevgen Levdansky, Jana Moravcová, David Potěšil, Zbyněk Zdráhal, Dominik Hřebík, Lucie Nepovímová, Torleif Tollefsrud Gjølberg, Jan Terje Andersen, Jiří Nováček, Tibor Füzik, and Pavel PlevkaProc. Natl. Acad. Sci. U.S.A., 2026, 123, e2601182123<div>&nbsp;</div><div><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1073/pnas.2601182123">https://doi.org/10.1073/pnas.2601182123</a></div><h6>licenced under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/">CC-BY 4.0</a></h6></blockquote><h4>Abstract</h4>Enteroviruses cause a broad spectrum of human diseases, ranging from mild respiratory or gastrointestinal infections to severe neurological disorders such as aseptic meningitis and encephalitis. Enterovirus cell entry involves receptor-mediated endocytosis followed by destabilizing rearrangements of the virus capsid that enable genome release. However, the mechanism of enterovirus genome release has not been visualized in infected cells. Here, we used cryoelectron tomography and microscopy to image echovirus 18 (E18) entry into host cells and its interaction with the neonatal Fc receptor (FcRn). 30 min postinfection, endosomes and cytoplasm contained empty capsids missing one or several pentamers of capsid proteins, providing evidence that in vivo E18 releases its genome through capsid opening. In vitro, FcRn binding induced the expulsion of pocket factors from hydrophobic pockets in VP1, priming the virus for uncoating. The cryoelectron microscopy reconstruction of genome-containing particles of E18 inside infected cells did not reveal pocket factors, indicating that receptor binding triggers the same priming process during infection. We did not detect activated particles in infected cells, suggesting that these intermediates are short-lived and rapidly release their genomes in vivo. Our results identify capsid opening as the in vivo mechanism of echovirus 18 genome release, providing structural evidence for a process previously only inferred from in vitro experiments.

CEITEC Scientists Are the First to Capture How Enteroviruses Initiate Infection 

Gas chromatography (GC) is a powerful analytical technique used to separate and analyze compounds in a mixture. Whether you're working in pharmaceuticals, environmental testing, or food safety, understanding the key components of a gas chromatograph is essential for accurate and efficient results.In this article, we will delve into the primary components of gas chromatography, including the injector, column, detector, and carrier gas—and explain how each plays a critical role in the separation and analysis process.By mastering these elements, you can optimize your GC setup for precise and reliable outcomes. Let's explore each component in detail:<h3>Sample Injector</h3>The injector is the starting point in the <a target="_blank" rel="noopener noreferrer" href="https://www.phenomenex.com/techniques/gc">gas chromatography process</a>, where the sample is introduced into the system. In GC, the sample must be vaporized into a gas before it enters the column. The injector serves this purpose by heating the sample to its gaseous state. There are many types of injectors, Split/Splitless, PTV, on column.The most common injector is the Split/Splitless injector that can be used in split mode or in splitless mode:<ul><li>Split Injection: This mode allows a portion of the sample to be sent to the column while the remainder is vented. It is useful for high-concentration samples to prevent system overload.</li><li>Splitless Injection: In this mode, the entire sample is introduced into the column, making it ideal for trace analysis where even minute quantities need detection.</li></ul>Proper choice of injector type and proper control of injection conditions, such as temperature, sample size, injection mode are crucial for achieving reproducible and reliable results.<h3>Carrier Gas</h3>In gas chromatography, the mobile phase is represented by carrier gas, which transports the vaporized sample through the column. The carrier gas is an inert gas, such as helium, nitrogen, or hydrogen. The choice of carrier gas can influence the efficiency of the separation process.<ul><li>Helium is the most used carrier gas due to its inertness and high flow rate.</li><li>Hydrogen offers faster analysis times but requires careful handling due to its flammability.</li><li>Nitrogen provides a cheaper solution compared to Helium, although it's slower than helium or hydrogen.</li></ul>The flow rate and pressure of the carrier gas need to be carefully controlled to ensure that the sample moves smoothly through the system and adequate efficiency is generated.<h3>Column/Stationary Phase</h3>The column is the heart of the gas chromatograph, where the actual separation of compounds occurs. <a target="_blank" rel="noopener noreferrer" href="https://labrulez.com/en-us/gcms/products?category=7&amp;manufacturerItems=50">GC columns</a> are typically long, thin tubes made from stainless steel or fused silica. They are coated with a stationary phase, which interacts with the components of the sample as they pass through.<ul><li>Packed Columns: These contain small particles of stationary phase material and generally have a larger volume. While they are less efficient than capillary columns, they can be suitable for specific applications.</li><li>Capillary Columns: These thin tubes are coated with a stationary phase, offering higher resolution and faster analysis times due to their smaller diameter.</li></ul>The length, diameter, and type of stationary phase of the column are important factors that affect the efficiency and selectivity of the separation. The choice of stationary phase (polar or non-polar; liquid-coated or solid) affects how different compounds interact with it.As the sample moves through the column, compounds separate based on volatility and their affinity for the stationary phase, resulting in distinct peaks in the chromatogram.<h3>Detector</h3>Once the sample has passed through the column, it reaches the detector, where individual components are identified and measured. There are several types of detectors, each suited to different applications:<ul><li>Flame Ionization Detector (FID): One of the most commonly used detectors in GC. It measures ions produced when organic compounds are burned in a hydrogen-air flame. FID is highly sensitive to a wide range of organic compounds and offers a broad linear dynamic range.</li><li>Thermal Conductivity Detector (TCD): Detects changes in the thermal conductivity of the gas stream as analytes elute from the column. It is a universal, non-destructive detector, but is generally less sensitive than FID.</li><li>Electron capture detector (ECD): A very sensitive and selective detector used to detect chlorinated compounds it is easily contaminated and requires very pure and dry carrier and makeup gases and difficult maintenance.</li><li>Mass Spectrometer (MS): Provides structural information, aiding in both identification and quantification. Requires advanced and trained users and it’s difficult to maintain.</li></ul>The choice of detector depends on the type of analysis being performed and the sensitivity required. Each detector converts physical or chemical changes associated with the analytes into a measurable signal, producing a chromatogram that reflects concentration and retention time.<h3>Data System</h3>Although not a physical part of the chromatograph, the data system plays an integral role in processing and interpreting the signals generated by the detector. Modern gas chromatographs are equipped with software that converts detector signals into chromatograms—visual representations of the separation process. The software allows users to quantify and identify the components of the sample based on retention times and peak areas.<h3>How to Read a Gas Chromatogram?</h3>Interpreting a gas chromatogram involves understanding its essential elements, such as peaks, retention times, and the overall data for qualitative and quantitative analysis.<h4>The Nature of the Sample</h4>Begin by considering the sample's characteristics; different samples, such as environmental pollutants or food components, may exhibit distinct peak patterns. Recognizing the baseline (the flat line representing the signal without analytes) is crucial for identifying peaks accurately. While well-defined peaks indicate successful separation of components, poorly shaped or broad peaks may suggest issues with the separation process. For instance, if a mixture is injected and three peaks are observed, it indicates the presence of three different compounds in the sample. Conversely, when evaluating the purity of a sample, one would anticipate observing a single peak. Ideally, the chromatogram should reflect this expectation, confirming the sample's purity.<h4>The Identity of the Sample</h4>Retention time (Rt) is a critical factor in identifying the compounds present in the sample. Each analyte has a characteristic retention time that can be compared to known standards or literature. To confirm identities, a standard mixture should run alongside the sample; this allows to correlate retention times with specific compounds. If available, utilizing MS in conjunction with gas chromatography (GC-MS) can provide additional structural information, enhancing identification accuracy. With HR-MS or MS-MS detectors, unknown compounds can be identified by matching perfectly the Molecular weight or by matching the fragmentation pattern.<h4>The Amount of Sample</h4>Quantifying analytes involves analyzing peak area or height, which is directly proportional to the concentration of the analyte in the sample. A calibration curve constructed from known concentrations can help relate peak areas to actual concentrations. It is essential to consider the detector’s sensitivity and the limits of detection, as peaks below a certain threshold may not provide reliable quantification.

Basic Principles of Gas Chromatography - Separation and Analysis

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Since its establishment in 2011, CEITEC has quickly developed into a cutting-edge infrastructure for research which performs highly alongside the best institutes in Europe. Among the main priorities of CEITEC are the promotion of a motivating and dynamic international scientific environment, the provision of state-of-the-art research infrastructure, and the policy of open communication and equal opportunities.

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Phenomenex is a global technology leader committed to developing novel analytical chemistry solutions that solve the separation and purification challenges of researchers in industrial, government and academic laboratories.

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The International Symposium on Chromatography (ISC) represents the oldest conference series focussing on separation science. ISC symposia have been organised since 1956 in each even year. ISC is internationally recognised as one of the premier meeting series for discussion of all modes of chromatography and separation science with a broad coverage of techniques and applications.

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Thermo Scientific Element GD Plus GD-MS

For high throughput and extra low ppb level detection limits, the Element GD Plus GD-MS is the most convenient and powerful tool for bulk metal analysis and depth profiling in routine and research applications.

Redefine the analysis of advanced high purity materials directly in solid state with the Thermo Scientific™ Element GD Plus™ GD-MS. For high throughput and extra low ppb level detection limits, the Element GD Plus GD-MS is the most convenient and powerful tool for bulk metal analysis and depth profiling in routine and research applications.The Element GD Plus GD-MS enables analysis of nearly all elements in the periodic table from both conductive and non-conductive materials with the same level of sensitivity and data quality. Analysis of low melting point metals such as gallium are made easy with a dedicated workflow for sample preparation and analysis. This makes GD-MS the reliable standard for any metal analysis.Almost all elements present in a solid sample can be detected and quantified routinely: many down to the parts per billion (ppb) level.<h3>High productivity and low cost of analysis</h3>The Element GD Plus GD-MS is designed to deliver outstanding sensitivity and accuracy at a high sample throughput, dramatically lowering the cost of your analysis.<ul><li>Fast-flow ion source</li><li>User-friendly source design: &lt; 1 min sample exchange</li><li>Short pumping times: &lt; 10 min sample turnaround</li><li>High sample throughput: up to 5 samples/hr</li><li>Less sample preparation: no requirement for acid cleaning of high-purity samples</li><li>Faster sample analysis: no requirement to measure calibration standards</li></ul><h3>Routine operation</h3>The Element GD Plus GD-MS is designed with routine operation and high throughput at its core.<ul><li>Linear dynamic range spanning more than 12 orders of magnitude allows the simultaneous analysis of matrix elements (%), traces (ppm), and ultra-traces (ppb)</li><li>Automatic cross-calibration between different detection modes ensures robust results</li><li>Sample vacuum chamber: eliminates risk of leakage between the sample and the GD cell</li><li>Determine elemental concentrations rapidly within a single scan without calibration standards (using standard RSF approach)</li><li>Best precision within a short analysis time</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Scientific_Element_GD_Plus_GD_MS_2_f0a37ee3f3.jpg" alt="Thermo Scientific™ Element GD Plus™ GD-MS: Ion Beam Ratio RSD for 10 min measurements of elements at 1000 ppm, 100 ppm and 1 ppm. Data shown for 18 different instruments." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Scientific_Element_GD_Plus_GD_MS_2_f0a37ee3f3.jpg 152w," sizes="100vw" width="906" height="931"><h3>Outstanding limits of detection</h3>The Element GD Plus GD-MS delivers high throughput without compromise. With the highest signal-to-noise ratio and lowest limits of detection, the Element GD Plus GD-MS is the workhorse for ultra-high purity elemental analysis.<ul><li>Unique ion source designed for high ion transmission, maximizing the signal analyzed.</li><li>Guaranteed signal-to-noise ratio produces the sub-ppb limits of detection</li><li>Optional CNO option achieves sub-ppm level limits of detection for CNO with no compromise to the through-put of your analysis</li><li>Factor 10 reduction of polyatomic interferences compared to static GD sources</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Scientific_Element_GD_Plus_GD_MS_3_a73bdae066.jpg" alt="Thermo Scientific™ Element GD Plus™ GD-MS: Typical mass spectrum of 42Ca and 45Sc during the analysis of high purity Ti. (Left) ASTM F1710-08 method using static source. (Right) Fast-flow method using the Element GD Plus GD-MS. Overlapping isobaric interference from 48Ti36Ar2+ and 50Ti40Ar2+ is suppressed by the fast flow source." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Scientific_Element_GD_Plus_GD_MS_3_a73bdae066.jpg 166w," sizes="100vw" width="921" height="867"><h3>Trust in results by high mass resolution</h3>The simplicity of high-resolution ICP-MS allows the most advanced performance, without compromising on straightforward and reliable method development.<ul><li>Interference-free measurements for indisputable analytical results</li><li>Any combination of resolution settings can be performed within a single analysis</li><li>Fixed-slit design guarantees maximum stability and reproducibility</li><li>Minimum contribution of high matrix signals on neighboring analyte peaks due to filter lens</li></ul><h3>Depth profiling with nanometer resolution</h3>Depth profiling is an important tool for elemental analysis of coatings and the assessment of element diffusion across layers.<ul><li>Depth resolution from nanometers to hundreds of micrometers</li><li>Determining concentrations of all elements from sub-ppm to 100% without the need for calibration</li><li>Flexible anode diameter for advanced depth profiling a</li><li>Sputter rates can be adjusted for bulk analysis or depth profiling</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Scientific_Element_GD_Plus_GD_MS_289a3c7919.jpg" alt="Thermo Scientific™ Element GD Plus™ GD-MS: Typical crater shape of a depth profile on a copper sample." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Scientific_Element_GD_Plus_GD_MS_289a3c7919.jpg 245w," sizes="100vw" width="1191" height="388"><h3>Recommended for</h3><ul><li>Aerospace: nickel superalloys, composite materials, depth profiling of coatings and diffusion layers</li><li>Microelectronics: copper, alumina powder, sputter targets</li><li>Renewable energy: silicon blocks, wafers, solar cells</li><li>Medical/pharmaceutical/food: stainless steel, alloys</li></ul><h3>Specifications</h3><ul><li>Type: GS Mass Spectrometer</li><li>Dynamic Range: &gt;10¹² Linear with Automatic Cross Calibration</li><li>Mass Resolution: 3 Fixed Resolutions: ≥300, ≥ 4,000, ≥ 10,000</li><li>Mass Stability: 25 ppm/8 hour</li><li>Power: 3-Phase, 230/400 V ± 10%, 50/60 Hz Fused 32 A / Phase</li><li>Sensitivity: &gt;1 x 10¹⁰ Cps (1.6 x 10⁻⁹ A) for Copper Peak (Peak Height, Total Ion Current) in Medium Resolution</li><li>Unit Size: Each</li></ul>

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ISC 2026 - Day 2

Basic Principles of Gas Chromatography - Separation and Analysis

CEITEC Scientists Are the First to Capture How Enteroviruses Initiate Infection