Genosensors as an alternative diagnostic sensing approaches for specific detection of virus species: A review of common techniques and outcomes.

Viral infections are responsible for the deaths of millions of people throughout the world. Since outbreak of highly contagious and mutant viruses such as contemporary sars-cov-2 pandemic, has challenged the conventional diagnostic methods, the entity of a thoroughly sensitive, specific, rapid and inexpensive detecting technique with minimum level of false-positivity or -negativity, is desperately needed more than any time in the past decades. Biosensors as minimized devices could detect viruses in simple formats. So far, various nucleic acid, immune- and protein-based biosensors were designed and tested for recognizing the genome, antigen, or protein level of viruses, respectively; however, nucleic acid-based sensing techniques, which is the foundation of constructing genosensors, are preferred not only because of their ultra-sensitivity and applicability in the early stages of infections but also for their ability to differentiate various strains of the same virus. To date, the review articles related to genosensors are just confined to particular pathogenic diseases; In this regard, the present review covers comprehensive information of the research progress of the electrochemical, optical, and surface plasmon resonance (SPR) genosensors that applied for human viruses' diseases detection and also provides a well description of viruses' clinical importance, the conventional diagnosis approaches of viruses and their disadvantages. This review would address the limitations in the current developments as well as the future challenges involved in the successful construction of sensing approaches with the functionalized nanomaterials and also allow exploring into core-research works regarding this area.

Label-free electrochemical microfluidic biosensors: futuristic point-of-care analytical devices for monitoring diseases.

The integration of microfluidics with electrochemical analysis has resulted in the development of single miniaturized detection systems, which allows the precise control of sample volume with multianalyte detection capability in a cost- and time-effective manner. Microfluidic electrochemical sensing devices (MESDs) can potentially serve as precise sensing and monitoring systems for the detection of molecular markers in various detrimental diseases. MESDs offer several advantages, including (i) automated sample preparation and detection, (ii) low sample and reagent requirement, (iii) detection of multianalyte in a single run, (iv) multiplex analysis in a single integrated device, and (v) portability with simplicity in application and disposability. Label-free MESDs can serve an affordable real-time detection with a simple analysis in a short processing time, providing point-of-care diagnosis/detection possibilities in precision medicine, and environmental analysis. In the current review, we elaborate on label-free microfluidic biosensors, provide comprehensive insights into electrochemical detection techniques, and discuss the principles of label-free microfluidic-based sensing approaches.

State of the art: Lateral flow assays toward the point-of-care foodborne pathogenic bacteria detection in food samples.

Diverse chemicals and some physical phenomena recently introduced in nanotechnology have enabled scientists to develop useful devices in the field of food sciences. Concerning such developments, detecting foodborne pathogenic bacteria is now an important issue. These kinds of bacteria species have demonstrated severe health effects after consuming foods and high mortality related to acute cases. The most leading path of intoxication and infection has been through food matrices. Hence, quick recognition of foodborne bacteria agents at low concentrations has been required in current diagnostics. Lateral flow assays (LFAs) are one of the urgent and prevalently applied quick recognition methods that have been settled for recognizing diverse types of analytes. Thus, the present review has stressed on latest developments in LFAs-based platforms to detect various foodborne pathogenic bacteria such as Salmonella, Listeria, Escherichia coli, Brucella, Shigella, Staphylococcus aureus, Clostridium botulinum, and Vibrio cholera. Proper prominence has been given on exactly how the labels, detection elements, or procedures have affected recent developments in the evaluation of diverse bacteria using LFAs. Additionally, the modifications in assays specificity and sensitivity consistent with applied food processing techniques have been discussed. Finally, a conclusion has been drawn for highlighting the main challenges confronted through this method and offered a view and insight of thoughts for its further development in the future.

Lateral flow assays (LFA) as an alternative medical diagnosis method for detection of virus species: The intertwine of nanotechnology with sensing strategies.

Viruses are responsible for multiple infections in humans that impose huge health burdens on individuals and populations worldwide. Therefore, numerous diagnostic methods and strategies have been developed for prevention, management, and decreasing the burden of viral diseases, each having its advantages and limitations. Viral infections are commonly detected using serological and nucleic acid-based methods. However, these conventional and clinical approaches have some limitations that can be resolved by implementing other detector devices. Therefore, the search for sensitive, selective, portable, and costless approaches as efficient alternative clinical methods for point of care testing (POCT) analysis has gained much attention in recent years. POCT is one of the ultimate goals in virus detection, and thus, the tests need to be rapid, specific, sensitive, accessible, and user-friendly. In this review, after a brief overview of viruses and their characteristics, the conventional viral detection methods, the clinical approaches, and their advantages and shortcomings are firstly explained. Then, LFA systems working principles, benefits, classification are discussed. Furthermore, the studies regarding designing and employing LFAs in diagnosing different types of viruses, especially SARS-CoV-2 as a main concern worldwide and innovations in the LFAs' approaches and designs, are comprehensively discussed here. Furthermore, several strategies addressed in some studies for overcoming LFA limitations like low sensitivity are reviewed. Numerous techniques are adopted to increase sensitivity and perform quantitative detection. Employing several visualization methods, using different labeling reporters, integrating LFAs with other detection methods to benefit from both LFA and the integrated detection device advantages, and designing unique membranes to increase reagent reactivity, are some of the approaches that are highlighted.

Quantification of phenolic acids by partial least squares Fourier-transform infrared (PLS-FTIR) in extracts of medicinal plants.

INTRODUCTION: Phenolic compounds are ubiquitous compounds found in all plants as their secondary metabolites. Phenols are becoming increasingly important particularly because of their beneficial effects on health. OBJECTIVE: To provide a faithful calibration model for the simultaneous determination and quantification of phenolic acids, as salicylic, vanillic, p-hydroxybenzoic acids, eugenol and thymol in different extracts of medicinal plants, a comparative study was made between two methods of infrared measurements based on attenuated total reflectance (ATR) and transmission. METHODS: Characteristic absorbance peak heights of mid-infrared spectra of individual phenolic acids were measured for the compounds. For partial least squares regression (PLS-R) calibration mixtures of phenolic acids, wavenumber ranges, spectra pretreatment and number of latent variables, were assayed to improve the prediction capability of models using different spectral preprocessing techniques after mean centring of infrared data. Plant extracts were prepared by using water/methanol and ethanolic extraction solvents followed by Fourier-transform infrared (FTIR)-spectrometry analysis. The concentrations of phenolic compounds contained in the extracts were obtained by using the best models selected of the PLS calibration. RESULTS: PLS-ATR-mid-infrared (MIR) measurement provided the most accurate results and offers a good methodology for the determination of phenolic acids. The analysis showed that the rate of phenolic acids and monoterpenic phenols in extracts of medicinal plants is in the same range obtained with the Folin-Ciocalteu method, which confirm that the developed method using PLS is therefore, highly specific and selective. CONCLUSION: The simultaneous direct quantification of various phenolic acids in different plant extracts was possible with a fast and simple methodology based on PLS-ATR-FTIR analysis.

Ethambutol-Loaded Solid Lipid Nanoparticles as Dry Powder Inhalable Formulation for Tuberculosis Therapy.

Ethambutol hydrocloride (EMB) is an anti-tuberculosis drug, which is commonly used as a protection agent against of unrecognized resistance to other drugs employed to treat this disease. Since oral form of EMB has some side effects and cellular toxicity, direct administration of EMB into lungs seems to be an attractive and reasonable option in order to overcome these side effects. Our main goal in this study was assessment of pulmonary administration through dry powder inhaler (DPI) using EMB-loaded solid lipid nanoparticles (SLNs). We prepared EMB-loaded SLNs using two techniques (hot homogenization and ultrasonication). DPI formulations were made by spray drying of EMB-loaded SLNs with and without mannitol. For investigation of flowbility of the prepared powders, Carr's index and Hausner ratio, and for in vitro deposition of the powders, Next Generation Impactor (NGI) analysis were used. The encapsulation efficiency and particle size of obtained particles were higher than 98% and sub-100 nm, respectively. Toxicity investigation of EMB-loaded SLNs via MTT assay showed biocompatibility and non-toxicity of the SLNs. Results of flowability and aerodynamic traits assessment of EMB-loaded SLN DPI powder confirmed the suitability of prepared powders. Overall, the attained results showed that EMB-loaded SLN DPI has high potential for direct treatment of tuberculosis.

Modulating tumor hypoxia by nanomedicine for effective cancer therapy.

Hypoxia, a characteristic feature of tumors, is indispensable to tumor angiogenesis, metastasis, and multi drug resistance. Hypoxic avascular regions, deeply embedded inside the tumors significantly hinder delivery of therapeutic agents. The low oxygen tension results in resistance to the current applied anti-cancer therapeutics including radiotherapy, chemotherapy, and photodynamic therapy, the efficacy of which is firmly tied to the level of tumor oxygen supply. However, emerging data indicate that nanocarriers/nanodrugs can offer substantial benefits to improve the efficacy of current therapeutics, through modulation of tumor hypoxia. This review aims to introduce the most recent advances made in nanocarrier mediated targeting of tumor hypoxia. The first part is dedicated to the approaches by which nanocarriers could be designed to target/leverage hypoxia. These approaches include i) inhibiting Hypoxia Inducer Factor (HIF-1α); ii) hypoxia activated prodrugs/linkers; and iii) obligate anaerobe mediated targeting of tumor hypoxia. The second part, details novel nanosystems proposed to modulate tumor hypoxia through tumor oxygenation. These methods seek to lessen tumor hypoxia through vascular normalization, or reoxygenation therapy. The reoxygenation of tumor could be accomplished by: i) generation of oxygen filled nanocarriers; ii) natural/artificial oxygen nanocarriers; and iii) oxygen generators. The efficacy of each approach and their potential in cancer therapy is further discussed.

Development of immunosorbents for the analysis of forchlorfenuron in fruit juices by ion mobility spectrometry.

The advantages of using smart materials as immunosorbents in the analysis of complex matrices by ion mobility spectrometry (IMS) have been highlighted in this study. A novel analytical method has been proposed for the sensitive, selective, and fast determination of residues of the plant growth regulator forchlorfenuron in fruit juices. Three different monoclonal antibodies (s3#22, p2#21, and p6#41) were employed for the production of immunosorbents, based on Sepharose gel beads, which were characterized in terms of loading capacity, solvent resistance, and repeatability for its use in solid-phase extraction (SPE). Immunosorbents that were prepared with antibody p6#44 provided the best performance, with a loading capacity of 0.97 µg, a 10% (v/v) 2-propanol tolerance, and a reusability of at least eight uses. The SPE procedure involved the use of a column with 0.15 g Sepharose beads, containing 0.5 mg antibody, which was loaded to 20 mL of the sample, washed with 2 mL of water plus 2 mL of 10% (v/v) 2-propanol, and eluted with 2 mL of 2-propanol. The cleaned extract was directly analyzed by IMS, giving a limit of detection of 2 µg L-1 with a relative standard deviation of 7.6%. Trueness was assessed by the analysis of blank grape and kiwifruit juice samples spiked with forchlorfenuron concentrations from 10 to 400 µg L-1, with recoveries from 80 to 115%. The analytical performance of the proposed immunosorbent was compared with conventional extraction and cleanup methods, such as QuEChERS and C18-based SPE, giving the cleanest extracts for accurate determinations of forchlorfenuron by IMS. Graphical abstract ᅟ.

Diagnosis of hepatitis via nanomaterial-based electrochemical, optical or piezoelectrical biosensors: a review on recent advancements.

This review (with 145 refs.) summarizes the progress made in the past years in the field of nanomaterial based rapid detection of hepatitis viruses. Following an introduction into the field (with subsection on the significance of hepatitis and on fundamentals of biosensors), conventional methods for detection of hepatitis are discussed, along with their limitationss. The next section covers electrochemical sensors, with subsections on voltammetric, amperometric, potentiometric, impedimetric and conductometric biosensors. A further large section covers optical methods, with subsections on methods based on fluorescence, photometry, surface plasmon resonance, surface-enhanced Raman scattering and chemiluminescence. A concluding section discusses current challenges and gives an outlook on potential future developments. Graphical abstract A schematic illustration of biosensor components applied for detection of hepatitis viruses.

Advances in nanomaterial based optical biosensing and bioimaging of apoptosis via caspase-3 activity: a review.

Caspase-3 plays a vital role in intrinsic and extrinsic pathways of programed cell death and in cell proliferation. Its detection is an important tool for early detection of some cancers and apoptosis-related diseases, and for monitoring the efficacy of pharmaceuticals and of chemo- and radiotherapy of cancers. This review (with 72 references) summarizes nanomaterial based methods for signal amplification in optical methods for the determination of caspase-3 activity. Following an introduction into the field, a first large section covers optical assays, with subsections on luminescent and chemiluminescence, fluorometric (including FRET based), and colorimetric assays. Further section summarize methods for bioimaging of caspase-3. A concluding section covers current challenges and future perspectives. Graphical Abstract ᅟ.

Ensuring food safety using aptamer based assays: Electroanalytical approach.

Aptamers, are being increasingly employed as favorable receptors for constructing highly sensitive biosensors, for their remarkable affinities towards certain targets including a wide scope of biological or chemical substances, and their superiority over other biologic receptors. The selectivity and affinity of the aptamers have been integrated with the wise design of the assay, applying suitable modifications, such as nanomaterials on the electrode surface, employing oligonucleotide-specific amplification strategies or, their combinations. After successful performance of the electrochemical aptasensors for biomedical applications, the food sector with its direct implication for human health, which demands rapid and sensitive and economic analytical solutions for determination of health threatening contaminants in all stages of production process, is the next field of research for developing efficient electrochemical aptasensors. The aim of this review is to categorize and introduce food hazards and summarize the recent electrochemical aptasensors that have been developed to address these contaminants.

Nanomaterial-based biosensors for detection of pathogenic virus.

Viruses are real menace to human safety that cause devastating viral disease. The high prevalence of these diseases is due to improper detecting tools. Therefore, there is a remarkable demand to identify viruses in a fast, selective and accurate way. Several biosensors have been designed and commercialized for detection of pathogenic viruses. However, they present many challenges. Nanotechnology overcomes these challenges and performs direct detection of molecular targets in real time. In this overview, studies concerning nanotechnology-based biosensors for pathogenic virus detection have been summarized, paying special attention to biosensors based on graphene oxide, silica, carbon nanotubes, gold, silver, zinc oxide and magnetic nanoparticles, which could pave the way to detect viral diseases and provide healthy life for infected patients.

A green analytical chemistry approach for lipid extraction: computation methods in the selection of green solvents as alternative to hexane.

There is a great interest in finding alternatives and green solvents in extraction processes to replace petroleum based solvents. In order to investigate these possibilities, computational methods, as Hansen solubility parameters (HSP) and conductor-like screening model for real solvent (COSMO-RS), were used in this work to predict the solvation power of a series of solvents in salmon fish lipids. Additionally, experimental studies were used to evaluate the performance in lipids extraction using 2-methyltetrahydrofurane, cyclopentyl methyl ether, dimethyl carbonate, isopropanol, ethanol, ethyl acetate, p-cymene and d-limonene compared with hexane. Lipid classes of extracts were obtained by using high performance thin-layer chromatography (HPTLC), whereas gas chromatography with a flame ionization detector (GC/FID) technique was employed to obtain fatty acid profiles. Some differences between theoretical and experimental results were observed, especially regarding the behavior of p-cymene and d-limonene, which separate from the predicted capability. Results obtained from HPTLC indicated that p-cymene and d-limonene extract triglycerides (TAGs) and diglycerides (DAGs) at levels of 73 and 19%, respectively, whereas the other studied extracts contain between 75 and 76% of TAGs and between 16 and 17% of DAGs. Fatty acid profiles, obtained by using GC-FID, indicated that saturated fatty acids (SFAs) between 19.5 and 19.9% of extracted oil, monounsaturated fatty acids (MUFAs) in the range between 43.5 and 44.9%, and PUFAs between 31.2 and 34.6% were extracted. p-Cymene and limonene extracts contained lower percentages than the other studied solvents of some PUFAs due probably to the fact that these unsaturated fatty acids are more susceptible to oxidative degradation than MUFAs. Ethyl acetate has been found to be the best alternative solvent to hexane for the extraction of salmon oil lipids. Graphical Abstract ᅟ.

Comparison of Mineral Contents in Three Different Tobacco Formulations.

We identified and quantified a variety of mineral elements in 18 tobacco samples purchased from a Tunisian market. In total, 25 mineral elements have been measured in cigarettes, water pipe tobacco, and smokeless tobacco using inductively coupled plasma-optical emission spectroscopy following microwave-assisted digestion. Statistical analyses were performed using SPSSTM, version 18.0. The lowest concentrations of all studied elements were observed in water pipe tobacco. Significantly higher concentrations of Al, Fe, Mg, Na, Ca, Cr, and Co were found in smokeless tobacco, while cigarettes brands contained the highest concentrations of K, Mn, Ni, Ba, and Sr. There was no significant difference between the mineral contents of local and foreign cigarettes and conventional and light cigarettes. Our findings demonstrated that local smokeless tobacco appears to be the most hazardous tobacco type. The concentration of minerals in light cigarettes was not significantly different from the concentration in conventional cigarettes.

Hard Cap Espresso Machines in Analytical Chemistry: What Else?

A hard cap espresso machine has been used in combination with liquid chromatography with molecular fluorescence detection for the determination of polycyclic aromatic hydrocarbons (PAHs) from contaminated soils and sediments providing appropriate extraction efficiencies and quantitative results. Naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benz[b]fluoranthene, benz[k]fluoranthene, benz[a]pyrene, dibenz[a,h]anthracene, benz[ghi]perylene, and indeno[1,2,3-cd]pyrene were used as target compounds. It should be mentioned that the pairs benz[a]anthracene-chrysene and dibenz[a,h]anthracene-benz[ghi]perylene peaks coelute under the employed chromatographic conditions; thus, those compounds were determined together. PAHs were extracted from 5.0 g of soil, previously homogenized, freeze-dried, and sieved to 250 µm, with 50 mL of 40% (v/v) acetonitrile in water at a temperature of 72 ± 3 °C. The proposed procedure is really fast, with an extraction time of 11 s, and it reduces the required amount of organic solvent to do the sample preparation. The obtained limit of detection for the evaluated PAHs was from 1 to 38 µg kg(-1). Recoveries were calculated using clean soils spiked with 100, 500, 1000, and 2000 µg kg(-1) PAHs with values ranging from 81 to 121% and good precision with relative standard deviation values lower than 30%. The method was validated using soil and sediment certified reference materials and also using real samples by comparison with ultrasound-assisted extraction, as reference methodology, obtaining statistically comparable results. Thus, the use of hard cap espresso machines in the analytical laboratories offers tremendous possibilities as low cost extraction units for the extraction of solid samples.

Determination of 3,4-methylenedioxypyrovalerone (MDPV) in oral and nasal fluids by ion mobility spectrometry.

A fast and sensitive methodology has been developed for the evaluation of the 3,4-methylenedioxypyrovalerone (MDPV) consumed. Based on ion mobility spectrometry (IMS), MDPV was directly determined in nasal fluids with a limit of detection (LOD) in the order of 22 ng mL(-1), which corresponds to an absolute amount of 33 ng of MDPV per swab. MDPV was also determined after liquid-liquid microextraction (LLME) in oral fluids to avoid matrix effects, obtaining a LOD value of 4.4 ng mL(-1) in oral fluid samples. The IMS spectrum for MDPV exhibited a peak with K0 = 1.210 ± 0.005 cm(2)V(-1) s(-1) at a drift time of 14.62 ms, the total analysis time being 4.5 min per oral fluid and 1.5 min per nasal fluid sample. Samples must be analyzed within 24 h following collection and dissolution in 2-propanol, based on the complementary stability studies.

Use of a versatile, easy, and rapid atmospheric monitor (VERAM) passive samplers for pesticide determination in continental waters.

The versatile, easy, and rapid atmospheric monitor (VERAM), a passive sampler device widely used for air monitoring, was evaluated as passive sampler for the determination of 23 pesticides in water. Gas chromatography with mass spectrometry detection was employed for determination of pesticides after microwave-assisted-extraction and specific clean-up of deployed samplers. The proposed methodology reached method detection levels from 2 to 10 ng pesticide per sampler. Sampling rate (Rs) was determined for every pesticide from an uptake isotherm study performed at three different concentration levels (50, 125, and 250 ng L-1). The obtained RS values ranged from 0.06 to 0.76 L d-1. The obtained limits of detection for a 24-h passive sampling were from 4 to 50 ng L-1. The effect of water parameters, such as temperature, pH, and ionic strength, were evaluated for their effect on pesticides retention using VERAMs. Pesticide RS values were independent of the water composition and increased on increasing temperature. Finally, the VERAM uptake was compared with that obtained using classic semipermeable membrane devices (SPMDs). This study is the first precedent for the use of VERAMs as passive samplers for the adsorption and concentration of pesticides in water and it confirms the satisfactory analytical figures of merit of VERAM as passive sampler of water. Graphical Abstract Scheme of water sampling of pesticides using versatile, easy, and rapid atmospheric monitor (VERAM) passive samplers.

Highly selective solid-phase extraction sorbents for chloramphenicol determination in food and urine by ion mobility spectrometry.

Different highly selective sorbents have been evaluated for the treatment of food and biological samples to determine chloramphenicol residues by ion mobility spectrometry (IMS). Combination of a selective solid-phase extraction (SPE) and dispersive liquid-liquid microextraction allowed a highly sensitive determination of chloramphenicol in water, milk, honey, and urine samples. The performance of selective SPE supports such as immunoaffinity chromatography (IAC) and molecular imprinted polymers (MIP) have been compared in terms of selectivity, sensitivity, trueness, precision, and reusability. Quantitative recoveries were obtained for chloramphenicol residues, ranging from 91 to 123 % for water, from 99 to 120 % for skimmed milk, and from 95 to 124 % for urine using IAC-IMS and MIP-IMS methods. Quantitative recoveries (from 88 to 104 %) were also achieved for honey samples using IAC-IMS, but low recoveries were obtained using MIP-IMS. The limit of quantification was set at 0.1 µg L-1 which is lower than the minimum required performance limit established by the EU. The proposed methodology is a simple and cost affordable alternative to chromatography methods for the highly sensitive and selective analysis of chloramphenicol residues in food and urine. Graphical Abstract Scheme for chloramphenicol determination by selective solid-phase extraction and ion mobility spectrometry.

Comparison of transflection and transmission FTIR imaging measurements performed on differentially fixed tissue sections.

The widespread and cost-effective use of transflection substrates in Fourier transform infrared (FTIR) imaging of clinical samples is affected by the presence of artefacts including the electric field standing wave (EFSW) and contributions from light dispersion. For IR-based diagnostics, the manifestation of undesirable artifacts can distort the spectra and lead to erroneous diagnosis. Nevertheless, there is no clear consensus in the literature about the degree of influence of these effects. The aim of this work is to contribute to this discussion by comparing transflection and transmission images of the same tissue. For this purpose two adjacent sections of the same tissue (lymphoma sample) were fixed onto a CaF2 window and a transflective slide for FTIR imaging. The samples in this case had a central area where based on morphology it was presumed the fixative did not penetrate to the same extent hence providing a comparable region for the two different substrates with a distinct physical/chemical difference. Transmission and transflection spectra from adjacent hyperspectral tissue images were combined in an extended dataset. Surprisingly, unsupervised hierarchical cluster analysis clustered together transflection and transmission spectra, being classified according to differences in tissue fixation instead of the geometry employed for the image acquisition. A more detailed examination of spectra from the peripheral zone of the tissue indicated that the main differences between the transflection and transmission spectra were: (1) a small shift of the amide I, (2) a larger "noise" component in the transflection spectra requiring more averaging to obtain representative spectra of tissue types, and (3) the phosphate bands were generally higher in absorbance in the transflection measurements compared to the transmission ones. The amide I shift and the larger spectral variance was consistent with results obtained in previous studies where the EFWS was present. The findings indicate that artifacts resulting from transflection measurements were small but consistent across the tissue, and therefore the use of transflection measurements could be employed for disease diagnosis. Accordingly, we recommend a straightforward multivariate comparison of images from transmission and transflection measurements in a combined data matrix obtained from adjacent sections of the tissue as a useful preliminary study for establishing the impact of the EFWS on the samples, before considering the routine use of transflection substrates for any new tissue studied.

Analysis of multi-source metabolomic data using joint and individual variation explained (JIVE).

Metabolic profiling is increasingly being used for understanding biological processes but there is no single analytical technique that provides a complete quantitative or qualitative profiling of the metabolome. Data fusion (i.e. joint analysis of data from multiple sources) has the potential to circumvent this issue facilitating knowledge discovery and reliable biomarker identification. Another field of application of data fusion is the simultaneous analysis of metabolomic changes through several biofluids or tissues. However, metabolomics typically deals with large datasets, with hundreds to thousands of variables and the identification of shared and individual factors or structures across multiple sources is challenging due to the high variable to sample ratios and differences in intensity and noise range. In this work we apply a recent method, Joint and Individual Variation Explained (JIVE), for the integrated unsupervised analysis of metabolomic profiles from multiple data sources. This method separates the shared patterns among data sources (i.e. the joint structure) from the individual structure of each data source that is unrelated to the joint structure. Two examples are described to show the applicability of JIVE for the simultaneous analysis of multi-source data using: (i) plasma samples subjected to different analytical techniques, sample treatment and measurement conditions; and (ii) plasma and urine samples subjected to liquid chromatography-mass spectrometry measured using two ionization conditions.