A team led by scientists from CEITEC Masaryk University has uncovered the infection mechanism of tailed bacteriophages – a group of viruses that infect bacteria. These phages target, among others, Staphylococcus aureus, a major cause of bacterial infections that is often resistant to antibiotics. The bacterium belongs to a group of Gram-positive bacteria characterised by an exceptionally thick cell wall. Although the infection mechanisms of some other bacteriophages have been described previously, the way tailed phages infecting Staphylococcus aureus and other thick-walled bacteria invade their hosts had remained unknown. The researchers have now revealed how such a bacteriophage breaches the protective barrier of the bacterial cell and delivers its genetic material inside. Their findings could contribute to the development of new strategies for combating antibiotic-resistant bacteria.Staphylococcus aureus is one of the most common sources of bacterial infections in humans. It can cause skin infections, pneumonia, and even life-threatening bloodstream infections. Moreover, many of its strains have become resistant to commonly used antibiotics, increasing interest in alternative treatment approaches such as bacteriophage therapy.“Bacteriophages are the most abundant biological entities on Earth and have been infecting bacteria for billions of years. Yet we still do not fully understand how they overcome the cell wall of certain Gram-positive bacteria. By reconstructing the bacteriophage structure before and after it attaches to a bacterial cell, we were able to reveal this process,” says <a target="_blank" rel="noopener noreferrer" href="https://www.ceitec.eu/jan-binovsky-ph-d/u91173?page=publication">Ján Bíňovský</a> of CEITEC Masaryk University, who led the study together with Marta Šiborová.Bacteriophage 812, investigated in this study, specifically infects Staphylococcus aureus. The researchers discovered that once it recognises the correct host, the protein structure at the tip of its tail undergoes extensive rearrangements. Individual components of this structure, which resembles a lunar landing module, reorganise into a new configuration that enables the virus to firmly attach to the bacterial surface. At the same time, a mechanism is activated that triggers contraction of the phage tail.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/CEITEC_Jak_zabit_zlateho_stafylokoka_novy_pohled_na_viry_ktere_si_poradi_s_bakteriemi_01c86d5e42.jpg" alt="CEITEC/Plevka Lab: How to Kill Staphylococcus Aureus: A New Insight into Viruses That Can Defeat Bacteria: Phage before attachment to the bacterial cell." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_CEITEC_Jak_zabit_zlateho_stafylokoka_novy_pohled_na_viry_ktere_si_poradi_s_bakteriemi_01c86d5e42.jpg 245w," sizes="100vw" width="4339" height="1600"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/CEITEC_Jak_zabit_zlateho_stafylokoka_novy_pohled_na_viry_ktere_si_poradi_s_bakteriemi_2_53422574db.jpg" alt="CEITEC/Plevka Lab: How to Kill Staphylococcus Aureus: A New Insight into Viruses That Can Defeat Bacteria: Phage attached to the bacterial cell." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_CEITEC_Jak_zabit_zlateho_stafylokoka_novy_pohled_na_viry_ktere_si_poradi_s_bakteriemi_2_53422574db.jpg 245w," sizes="100vw" width="4085" height="1600">“The process resembles the release of an extended spring. The bacteriophage tail contracts to approximately half of its original length, and the released energy drives the central tube through the bacterium's protective layers. The virus can then deliver its genetic material into the cell and initiate infection,” explains Marta Šiborová.Unlike many other bacteria, Staphylococcus aureus possesses an exceptionally thick cell wall. The researchers therefore investigated in detail how the bacteriophage overcomes this barrier. They found that the virus employs a combination of mechanical force and enzymatic activity. Some components of its infection apparatus likely disrupt teichoic acids, which form the outer protective layer of the bacterial cell wall. Other proteins then degrade peptidoglycan, the main structural component of the cell wall. Finally, the bacteriophage penetrates the inner lipid membrane, allowing its central tube to enter the bacterial cell.The findings show that the bacteriophage does not function as a simple "needle", but rather as a sophisticated nanomachine composed of dozens of cooperating proteins.Although this is fundamental research, the findings may prove important for future medical applications. Bacteriophages are considered one of the promising alternatives for treating infections caused by antibiotic-resistant bacteria.“If we want to use bacteriophages therapeutically in the future – or even engineer them for specific medical applications – we first need to understand in detail how they work. Our study provides fundamental insight into how bacteriophages recognise their hosts and initiate infection,” says <a target="_blank" rel="noopener noreferrer" href="https://www.ceitec.eu/pavel-plevka-ph-d/u26854">Pavel Plevka</a>, structural biologist and head of a research group at CEITEC Masaryk University.<blockquote>The study, published in <a target="_blank" rel="noopener noreferrer" href="https://link.springer.com/article/10.1038/s44318-026-00834-9">EMBO Journal</a>, also involved researchers from the Faculty of Science, Masaryk University.</blockquote><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/CEITEC_Jak_zabit_zlateho_stafylokoka_novy_pohled_na_viry_ktere_si_poradi_s_bakteriemi_3_fba5a65145.jpg" alt="CEITEC/Plevka Lab: How to Kill Staphylococcus Aureus: A New Insight into Viruses That Can Defeat Bacteria: Black = protein structure at the tip of the tail after the conformational change; red = portion of the tail that has begun to contract; blue = portion of the tail that remains extended." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_CEITEC_Jak_zabit_zlateho_stafylokoka_novy_pohled_na_viry_ktere_si_poradi_s_bakteriemi_3_fba5a65145.jpg 245w," sizes="100vw" width="1600" height="782"><blockquote><h4>The original article</h4><h4><a target="_blank" rel="noopener noreferrer" href="https://link.springer.com/article/10.1038/s44318-026-00834-9">Conformational changes of the baseplate regulating tail contraction of Staphylococcus phage 812</a></h4>Ján Bíňovský, Marta Šiborová, Maryna Zlatohurska, Jiří Nováček, Pavol Bárdy, Roman Baška, Karel Škubník, Tibor Botka, Martin Benešík, Roman Pantuček, Konstantinos Tripsianes &amp; Pavel PlevkaEMBO J (2026)<a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1038/s44318-026-00834-9">https://doi.org/10.1038/s44318-026-00834-9</a>&nbsp;<h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/">CC-BY 4.0</a></h6></blockquote>

 How to Kill Staphylococcus Aureus: A New Insight into Viruses That Can Defeat Bacteria 

The standard uncertainty arising from random effects is often derived from repeated experiments and is quantified in terms of the standard deviation s of the measured values of the quantity. If it is the standard uncertainty arising from random effects on a single measurement that is required, then the observed standard deviation s is used without change. However, for a result which is the mean x of n measurements the standard uncertainty decreases as n increases, so that:<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Eurachem_Using_repeated_measurements_to_improve_the_standard_uncertainty_equation_1_19f8f07f8f.jpg" alt="Eurachem: Using repeated measurements to improve the standard uncertainty - Equation 1" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Eurachem_Using_repeated_measurements_to_improve_the_standard_uncertainty_equation_1_19f8f07f8f.jpg 245w," sizes="100vw" width="485" height="138">Example 1 shows how Eq (1) applies when estimating the uncertainty of a mean value, but not when considering the uncertainty of individual observations.<blockquote>Example 1 A volumetric pipette is calibrated with 12 measurements; the mean and the standard deviation are calculated. Eq. 1 applies to estimate the standard uncertainty of the mean value. However, when using the pipette to deliver one aliquot, Eq. 1 does not apply and the standard uncertainty due to random variation on this single measurement is the standard deviation s</blockquote>For Eq (1) to be valid, it is a requirement that all the measurements are independent and from a stable test sample under the same measurement conditions. The measurement conditions for all the measurements could be, for example, 1) repeatability conditions, 2) intermediate precision (within laboratory reproducibility) conditions or 3) reproducibility conditions&nbsp;It is very important to be aware that the standard uncertainty given by Eq. 1 only gives the estimated uncertainty due to random variation under the conditions of measurement under which the observations were taken, and is only strictly valid for independent observations.&nbsp;It can be hard to decide whether observations are sufficiently independent for Eq. 1 to apply, as there is no simple, general, rule. The following paragraphs therefore give examples of different circumstances to help identify circumstances when Eq. 1 can safely be used.<h3>Example where Equation (1) applies&nbsp;</h3><h4>Measurement of inhomogeneous samples&nbsp;</h4>If inhomogeneity for test samples is a major part of the uncertainty the analyst may choose to measure more test portions from each test sample in order to reduce the standard uncertainty. If all these measurements are made under repeatability conditions, i.e. the same measurement conditions following the whole procedure, including repeated random sampling from the test sample, the standard deviation of the mean, given by Eq. (1), should be used to estimate the uncertainty arising from variation under repeatability conditions.&nbsp;<h3>Examples where Equation (1) does not apply&nbsp;</h3>The following paragraphs give two examples where neither the standard deviation nor the standard deviation of the mean can be directly applied without further analysis of the data.&nbsp;<h4>Measurements taken in groups&nbsp;</h4>One example is when we have data from internal quality control from a measurement procedure that includes a calibration before analysis each day. We want to calculate the standard uncertainty of the mean value used to set the central line in the QC chart. The data consist of duplicate QC measurements performed on a stable test sample each day over a longer period of time (say, p days), giving a total of 2p observations; that is, p groups of two measurements. Because each pair of duplicate measurements has a single calibration error in common; the duplicates within the data set are not strictly independent and Eq. (1) cannot be directly used for all 2p observations. The uncertainty of the mean can most easily be calculated by taking the standard deviation of the p means for each day and dividing that standard deviation by √p . Analysis of variance can also be useful in similar cases. Similar principles apply to other kinds of grouping, including grouping by operator, instrument etc.&nbsp;<h4>Measurement when the test item or measurement system is not stable over time</h4>Another common example is time dependent data. The time dependence could be due to instrument drift or to actual change in concentration by time. In such cases the error for a given observation is partly random and in part ‘carried over’ from the previous observation. Again the errors affecting each observation are not independent because some part of the error is common to successive observations; Eq. (1) can not be used and more complex statistical techniques, that allow for correlation, must be used to process the data.&nbsp;For further guidance on the treatment of correlated data in uncertainty evaluation, see Eurolab Technical Report 1/2006: Guide to the Evaluation of Measurement Uncertainty for Quantitative Test Results, Appendix A.5

Using repeated measurements to improve the standard uncertainty

Our Library never stops expanding. What are the most recent contributions to LabRulezICPMS Library in the week of 27th July 2026? Check out new documents from the field of spectroscopy/spectrometry and related techniques!<blockquote>👉 <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library">SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT SPECTROSCOPY/SPECTROMETRY RELATED TECHNIQUES</a></blockquote><blockquote>👉 Need info about different analytical techniques? Peek into <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library">LabRulezLCMS</a> or <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library">LabRulezGCMS</a> libraries.</blockquote>This week we bring you application notes by Agilent Technologies, Shimadzu and Thermo Fisher Scientific!<h3>1. Agilent Technologies: High-Precision Determination of Phosphorus and Potassium in Fertilizers by ICP-OES</h3>Accurate nutrient analysis of fertilizers using an <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library?mainauthorItems=10&amp;search=5800">Agilent 5800 ICP-OES</a> and standard bracketing<ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_fertilizers_standard_bracketing_5800_icp_oes_5994_9311en_agilent_83cbca87fd.pdf">Full PDF for download</a>&nbsp;</li></ul>Accurate characterization of fertilizer nutrient content is critical for optimizing plant growth, maximizing yield, and ensuring sustainable agricultural practices. Fertilizers must comply with strict regulatory specifications, particularly for declared NPK (nitrogen–phosphorus–potassium) ratios, which define the relative nutrient content supplied to crops. Even small deviations from the specified ratio can impact plant yield, regulatory compliance, customer confidence in the product, as well as its commercial value.&nbsp;Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) is a well-established technique for multi-element analysis of complex samples, so is ideally suited to meet the precision and accuracy requirements of fertilizer testing.1,2 However, applications that require very tight tolerances, such as NPK verification, benefit from enhanced calibration approaches as even small deviations from reported values can have large financial implications for the manufacturer.Using Agilent ICP-OES instruments, standard bracketing calibration based on a standard–sample–standard measurement sequence, minimizes the impact of sample-to-sample variability and matrix effects.3,4 This approach further improves analytical precision and accuracy compared to conventional external calibration, making it a particularly valuable method for analyzing fertilizers with tightly controlled specifications.&nbsp;In this study, an Agilent 5800 Vertical Dual View (VDV) ICP-OES, equipped with an Agilent SPS 4 autosampler and controlled using Agilent ICP Expert Pro software,5 was used to determine P and K concentrations and corresponding NPK ratios in a standard reference material (SRM) and two commercially available fertilizers. The standard bracketing method was adapted from ISO methods 11494 and 114956,7 and adjusted for fertilizer analysis. The performance of the method, when combined with real-time data processing tools, was evaluated for accuracy and precision.<h4>Experimental&nbsp;</h4><h5>Instrumentation&nbsp;</h5>The <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library?mainauthorItems=10&amp;search=5800">Agilent 5800 VDV ICP-OES </a>was configured with the <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library?mainauthorItems=10&amp;search=SPS+4+autosampler">Agilent SPS 4 autosampler</a>, which provided automated sample delivery to the instrument (Figure 1). The 5800 ICP-OES was equipped with an Agilent SeaSpray nebulizer, double-pass cyclonic spray chamber, and one-piece VDV torch with a 1.8 mm internal diameter (ID) injector. All components were controlled by Agilent ICP Expert Pro* software. Instrument operating parameters are listed in Table 1.<h4>Conclusion&nbsp;</h4>This study demonstrates the effectiveness of the Agilent 5800 VDV ICP-OES standard bracketing method for high-precision determination of phosphorus and potassium in fertilizers. The method delivered excellent performance, with relative standard deviations below 0.1% and excellent agreement with expected NPK values, with recoveries ranging from 99 to 102%. The combination of gravimetrically prepared standards, internal standard correction, and bracketing calibration minimizes analytical variability and ensures reliable results for fertilizer quality control.&nbsp;In addition, Agilent ICP Expert Pro software streamlines analysis through real-time calculations and automated quality control tools, improving laboratory efficiency and reducing the risk of reporting errors. This approach provides a robust and practical solution for high throughput fertilizer testing laboratories, enabling precise NPK verification that strengthens regulatory compliance, reduces the risk of mislabeling, and supports accurate product pricing.<h3>2. Shimadzu: Multifaceted Evaluation of Frozen Tempura Batter Coating Focusing on Food Texture</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_01_00987_en_f919b540e7.pdf">Full PDF for download</a></li></ul>The “deliciousness” of foods consists of multiple factors, including taste, smell, and visual appeal. However, texture, sometimes called “mouthfeel,” is also one extremely important factor. Mouthfeel refers to the physical sensations experienced when food is placed in the mouth or chewed, and is expressed by various onomatopoeic words such as “crisp” and “chewy.” Among these, the packaging of some foods uses onomatopoeic terms to emphasize the appeal of their distinctive textures, and this has become an important “selling point” for consumers when deciding which product to select.&nbsp;In the development of food products, the method of evaluating texture has become a key point. Sensory methods have long been used, but because sensory evaluations depend on the human senses, they are easily influenced by differences between individuals conducting the evaluation and their physical condition.Thus, the difficulty in ensuring repeatability is an issue. As an additional issue, technical training for the panelists who conduct evaluations also requires time and labor. To compensate for these problems, evaluation methods based on measurement of physical properties with instruments may be used. This approach eliminatesthe human error that had been a problem with sensory evaluations, enabling objective evaluations.&nbsp;Food texture is also complexly influenced by the interactions of various factors, such as the ingredients contained in the food, their amounts, and the cooking method. Since differences in these factors may appear in the structure and surface condition of foods, observation and measurement of the internalstructure and surface condition of foods make it possible to analyze and understand the factors that contribute to texture, allowing more efficient food product development from the physical viewpoint. This article introduces an example of an analysis of the differencesin texture that occur due to differences in the heating method from the aspects of evaluation of physical properties and structural and surface observation, using frozen tempura asthe testsample.<h4>Experiment&nbsp;</h4>In this experiment, four instruments were used for evaluation of mechanical properties and structural and surface observation. Table 1 shows the names of the instruments, the purpose of the experiment, and the corresponding sectionsin this article. The test samples used here were commercially-available frozen tempura, which features “moistness” when prepared by microwave oven cooking and “crispness” after microwave oven + oven cooking. The “Moist” type is prepared by heating for 1 min in a microwave oven, and the “Crisp” type is prepared by additional heating in an oven after microwave heating. Since the heating time in the oven is adjusted depending on the sample size required by each instrument, the specific sample preparation procedure and the flow of the tests will be described in the sections concerning each instrument.<h5>Evaluation of Coating Surface Roughness by Laser Microscope&nbsp;</h5>The laser microscope was used in high-magnification measurements of the roughness of the sample surface and color observation (color images). It is possible to grasp the differences in the batter coatings of the “Moist” and “Crisp” types from changes in roughness and also changes in color. Fig. 11 shows the appearance of the OLS5500 laser microscope used here. In this instrument, optical resolution is enhanced by using a singlewavelength 405 nm laser beam, and topographical information can be acquired by reflective confocal laser microscopy. Color images of the same field can also be obtained by using a white LED.In this experiment, the samples were prepared by the following procedure in order to observe the same areas of the “Moist” and “Crisp” samples. First, the entire kabocha tempura was heated for 1 min in the microwave oven, after which part of the sample was cut off and observed on the stage (Fig. 12). Following this, the observed sample was heated in the oven and placed on the stage again, and the “Crisp” sample was observed (Fig. 13). To observe the shape of a wide area of the sample, an alignment (“tile-stitching”) function was used. The image acquisition condition was the ultra-high speed mode using a 20x objective lens.<h4>Conclusion&nbsp;</h4>A sensory evaluation and evaluation of physical properties using a texture analyzer, and structural observations from the macro to the micro level using an X-ray CT, laser microscope, and SEM were conducted for frozen tempura with different food textures depending on the heating conditions. The impression of the food texture, or “mouthfeel,” obtained in the sensory evaluation was quantified in the form of physical property values by using the texture analyzer, and the factors that formed the grounds for those numerical values were then evaluated based on the results of various types of observation. As a result, it was suggested that differences in food texture correspond to changes in the food structure and oil content.&nbsp;In this experiment, different samples were examined with four types of instruments. However, if physical property tests can be carried out with the samples as-is after observation of the same areas, a more direct and high accuracy analysis is considered to be possible. Moreover, in this experiment, the food texture was changed by using different heating methods, but in cases where the ingredients (flour, oil) or the deep-frying method is changed, there is a possibility that different factors from those in this study may contribute to the texture. As demonstrated in this experiment, although “food texture” is often grasped sensorily, as suggested by the term “mouthfeel,” this property can be visualized scientifically in terms of the structure and physical properties of the food and the condition of the oil content by combining multifaceted evaluations using multiple instruments. This technique is expected to become an effective approach for reproducing and controlling the target texture in food product development and quality design.<h3>3. Thermo Fisher Scientific: Bauxite analysis with Niton XRF analyzers</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/labrulez-bucket-strapi-h3hsga3/bauxite_analysis_with_niton_xrf_analyzers_an1795_en_93b319a76e.pdf">Full PDF for download</a></li></ul>Globally, bauxite is the primary source of aluminum (Al) ore and anchors a major industry in many countries, including China, Australia, and Brazil. As such, grading Al concentration is of paramount interest in the mine as is the need to determine concentrations of penalty elements. The desired goal is to conduct all the analysis in a way that maximizes productivity.&nbsp;<h4>Application&nbsp;</h4>Analysis of aluminum (Al), silicon (Si), and iron (Fe) presents unique challenges. Accurate analysis of all three is critical for ore grading and understanding their influence on the processing and production of the primary metal of interest. Relying on lab-analysis only in bauxite mining operation often results in costly time delays and reduced productivity while waiting hour if not days and weeks for the results.&nbsp;With the ruggedized, dust- and splash-proof <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/products/1997">Thermo Scientific™ Niton™ XL3t GOLDD+ XRL Analyzer</a>, near lab-quality analysis of Al, Si and Fe can be generated on sites, enabling quick decisions in at remote mines. Indeed, the Niton XL3t GOLDD+ analyzer provides rapid and accurate elemental analyses of bauxite ore enabling to map chemical concentrations in realtime, identify excavation hotspots and detect penalty elements.&nbsp;<h4>Handheld XRF analyzer&nbsp;</h4>Thermo Scientific Niton Handheld XRF analyzers, including the Niton XL3 GOLDD+ analyzer, easily analyze elements from magnesium (Mg) to uranium (U) to fill all exploration and mining needs. These instruments make it easy to perform trend analysis by averaging readings in real-time or by downloading results later to a PC. They deliver fast, accurate elemental analysis for intensive metals exploration and production whether base metals, precious metals, or even rare earth elements.<h4>Comments&nbsp;</h4>The correlation coefficients and repeatability data for the key elements in bauxite analysis demonstrate the excellent accuracy and precision of the handheld Niton XL3 950 GOLDD+ analyzer, indicating that the Niton XL3 GOLDD+ instrument is ideal for fast mine or field analysis. The instant chemical information it provides allows the user to make critical decisions with minimal downtime, keeping projects running and productive. Additionally, they provide information that minimizes the expense and time of shipping samples for analysis and increases savings. The Thermo Scientific Niton XRF analyzer is a great addition to any process in the life of the mine.

News from LabRulezICPMS Library - Week 31, 2026

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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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Eurachem is a European network promoting international traceability of chemical measurements and good analytical practice. It provides expert guidance, supports method validation, uncertainty evaluation, proficiency testing, and facilitates discussion on technical and policy issues in analytical quality.

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rHGH fragment or AOD-9604 (LCMS+CHNS) analysis

Combined LC-MS, CHNS and HPLC analysis of rHGH fragment 176–191 and AOD-9604 for identification, amount, peptide purity and contamination screening.

This analysis is designed to identify and determine the amount and purity of recombinant Human Growth Hormone fragment 176–191 and AOD-9604. It combines LC-MS, CHNS and HPLC to provide information about peptide identity, net peptide content, peptide purity and potential contamination with other peptides or degradation products.The test can detect and measure either target compound. It is therefore not necessary to know in advance whether the sample contains rHGH fragment 176–191 or AOD-9604.<h4>rHGH Fragment 176–191</h4>rHGH fragment 176–191, also known as somatropin 176–191, is a peptide corresponding to amino acids 176 to 191 of Human Growth Hormone. It consists of 16 amino acids and represents the C-terminal region of the HGH molecule.Its molecular weight is approximately 1,799 Da. It differs from AOD-9604 in the first amino acid of its sequence.<h4>AOD-9604</h4>AOD-9604 is a synthetically modified peptide derived from Human Growth Hormone fragment 176–191. Like the rHGH fragment, it contains 16 amino acids, but its sequence begins with tyrosine instead of phenylalanine.This structural difference allows the two peptides to be distinguished by LC-MS. The molecular weight of AOD-9604 is approximately 1,815 Da.<h4>Analytical Methods</h4><h5>LC-MS – Identification and Contamination Screening</h5>LC-MS is used to confirm the identity of the peptide in the sample. It also provides screening for detectable contamination with other peptides and peptide degradation products.<h5>CHNS – Net Peptide Content Determination</h5>CHNS elemental analysis measures the carbon, hydrogen, nitrogen and sulphur content of the sample. The measured values can be used to determine Net Peptide Content.Because the sample is combusted during CHNS analysis, the result is not affected by solubility issues that may complicate chromatographic measurement of peptide amount.<h5>HPLC – Peptide Purity Determination</h5>HPLC is used to determine peptide purity and the relative proportion of the main peptide component compared with chromatographically detectable impurities.<h4>What the Analysis Determines</h4><ul><li>Identity of rHGH fragment 176–191 or AOD-9604</li><li>Amount of peptide in the sample</li><li>Net peptide content determined by CHNS</li><li>Peptide purity determined by HPLC</li><li>Presence of other peptides or degradation products detected by LC-MS</li><li>Differentiation between rHGH fragment 176–191 and AOD-9604</li></ul><h4>Analysis Parameters</h4><ul><li>Target compounds: rHGH fragment – somatropin 176–191 and AOD-9604</li><li>CAS number of AOD-9604: 221231-10-3</li><li>Molecular weight of AOD-9604: 1,815 Da</li><li>AOD-9604 sequence: H-Tyr-Leu-Arg-Ile-Val-Gln-Cys(1)-Arg-Ser-Val-Glu-Gly-Ser-Cys(1)-Gly-Phe-OH</li><li>CAS number of rHGH fragment: 66004-57-7</li><li>Molecular weight of rHGH fragment: 1,799 Da</li><li>rHGH fragment sequence: H-Phe-Leu-Arg-Ile-Val-Gln-Cys(1)-Arg-Ser-Val-Glu-Gly-Ser-Cys(1)-Gly-Phe-OH</li><li>Identification method: LC-MS</li><li>Amount determination method: CHNS</li><li>Peptide purity method: HPLC</li><li>Detection limit: less than one twentieth of the usual dosage per vial</li><li>Result format for lyophilizates: mg per vial and peptide purity</li><li>Alternative result format: m/m purity and peptide purity</li><li>Minimum lyophilizate sample: one whole unopened vial containing the lyophilizate</li><li>Minimum raw API powder sample: 30 mg in a sealed glass vial to prevent moisture absorption</li><li>Average turnaround time: 7 business days</li></ul><blockquote><h5>Important Notice</h5>The alternative m/m purity result format is intended exclusively for raw API powders. For lyophilized samples, the standard result format provides the peptide amount in mg per vial together with peptide purity.</blockquote><h4>Additional Analyses</h4><h5>TFA Analysis</h5><ul><li>Detection and measurement of trifluoroacetic acid (TFA) in the sample. Results are reported in mg per vial.</li></ul><h5>Raw Data</h5><ul><li>Delivery of the available raw analytical data from the primary test and all applicable additional analyses.</li></ul><h5>Fentanyl Presence Analysis</h5><h5>Alternative Result Format – m/m Purity</h5><ul><li>Alternative reporting of the result as mass-by-mass purity. This option is intended exclusively for raw API powders.</li></ul><h5>Variance Testing</h5><ul><li>Analysis of multiple sample units to assess variation within a single batch. All submitted samples must originate from the same batch of the same product.</li></ul><h5>pH Measurement</h5><h5>Endotoxin Analysis</h5><ul><li>Measurement of bacterial endotoxins, particularly lipopolysaccharides (LPS), in the sample. This analysis is available only for finished products and should not be ordered for raw powders.</li><li>The standard test provides accurate results up to 10 EU per vial. Values above 10 EU per vial are estimated and require an additional test with a different dilution for precise determination. Sending two vials is therefore recommended.</li><li>Where endotoxin levels above 10 EU per vial are expected, the method can be calibrated for the higher range in advance.</li></ul><h5>Additional Report</h5><ul><li>A separate additional laboratory report issued under a different client name.</li></ul><h5>Sterility Testing</h5><ul><li>TAMC and TYMC testing checks the product for the presence of bacteria, yeasts and moulds. Additional unopened sample units must be submitted for analysis. The average turnaround time for this test is 14 days.</li></ul><h5>Heavy Metals Analysis</h5><ul><li>Detection of arsenic, cadmium, lead and mercury in the sample. Testing for other metals can be arranged individually.</li></ul>

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How to Kill Staphylococcus Aureus: A New Insight into Viruses That Can Defeat Bacteria

News from LabRulezICPMS Library - Week 31, 2026

Using repeated measurements to improve the standard uncertainty