Detection of norovirus capsid protein in authentic standards and in stool extracts by matrix-assisted laser desorption ionization and nanospray mass spectrometry

An approach to zwitterionic peptide design for colorimetric detection of the Southampton norovirus SV3CP protease

Noroviruses are highly contagious and are one of the leading causes of acute gastroenteritis worldwide. Due to a lack of effective antiviral therapies, there is a need to diagnose and surveil norovirus infections to implement quarantine protocols and prevent large outbreaks. Currently, the gold standard of diagnosis uses reverse transcription polymerase chain reaction (RT-PCR), but PCR can have limited availability. Here, we propose a combination of a tunable peptide substrate and gold nanoparticles (AuNPs) to colorimetrically detect the Southampton norovirus 3C-like protease (SV3CP), a key protease in viral replication. Careful design of the substrate employs a zwitterionic peptide with opposite charged moieties on the C- and N- termini to induce a rapid color change visible to the naked eye; thus, this color change is indicative of SV3CP activity. This work expands on existing zwitterionic peptide strategies for protease detection by systematically evaluating the effects of lysine and arginine on nanoparticle charge screening. We also determine a limit of detection for SV3CP of 28.0 nM with comparable results in external breath condensate, urine, and fecal matter for 100 nM of SV3CP. The key advantage of this system is its simplicity and accessibility, thus making it an attractive tool for qualitative point-of-care diagnostics.

Deciphering the Virus Signal Within the Marine Dissolved Organic Matter Pool

Viruses are ubiquitously distributed in the marine environment, influencing microbial population dynamics and biogeochemical cycles on a large scale. Due to their small size, they fall into the oceanographic size-class definition of dissolved organic matter (DOM; <0.7 μm). The purpose of our study was to investigate if there is a detectable imprint of virus particles in natural DOM following standard sample preparation and molecular analysis routines using ultrahigh-resolution mass spectrometry (FT-ICR-MS). Therefore, we tested if a molecular signature deriving from virus particles can be detected in the DOM fingerprint of a bacterial culture upon prophage induction and of seawater containing the natural microbial community. Interestingly, the virus-mediated lysate of the infected bacterial culture differed from the cell material of a physically disrupted control culture in its molecular composition. Overall, a small subset of DOM compounds correlated significantly with virus abundances in the bacterial culture setup, accounting for <1% of the detected molecular formulae and <2% of the total signal intensity of the DOM dataset. These were phosphorus- and nitrogen-containing compounds and they were partially also detected in DOM samples from other studies that included high virus abundances. While some of these formulae matched with typical biomolecules that are constituents of viruses, others matched with bacterial cell wall components. Thus, the identified DOM molecular formulae were probably not solely derived from virus particles but were partially also derived from processes such as the virus-mediated bacterial cell lysis. Our results indicate that a virus-derived DOM signature is part of the natural DOM and barely detectable within the analytical window of ultrahigh-resolution mass spectrometry when a high natural background is present.

Mass Spectrometry-Based System for Identifying and Typing Norovirus Major Capsid Protein VP1

Norovirus-associated diseases are the most common foodborne illnesses worldwide. Polymerase chain reaction-based methods are the primary diagnostics for clinical samples; however, the high mutation rate of norovirus makes viral amplification and genotyping challenging. Technological advances in mass spectrometry (MS) make it a promising tool for identifying disease markers. Besides, the superior sensitivity of MS and proteomic approaches may enable the detection of all variants. Thus, this study aimed to establish an MS-based system for identifying and typing norovirus. We constructed three plasmids containing the major capsid protein VP1 of the norovirus GII.4 2006b, 2006a, and 2009a strains to produce virus-like particles for use as standards. Digested peptide signals were collected using a nano-flow ultra-performance liquid chromatography mass spectrometry (nano-UPLC/MS^E) system, and analyzed by ProteinLynx Global SERVER and TREE-PUZZLE software. Results revealed that the LC/MS^E system had an excellent coverage rate: the system detected more than 94% of amino acids of 3.61 femtomole norovirus VP1 structural protein. In the likelihood-mapping analysis, the proportions of unresolved quartets were 2.9% and 4.9% in the VP1 and S domains, respectively, which is superior to the 15.1% unresolved quartets in current PCR-based methodology. In summary, the use of LC/MS^E may efficiently monitor genotypes, and sensitively detect structural and functional mutations of noroviruses.

Application and Perspectives of MALDI-TOF Mass Spectrometry in Clinical Microbiology Laboratories

Early diagnosis of severe infections requires of a rapid and reliable diagnosis to initiate appropriate treatment, while avoiding unnecessary antimicrobial use and reducing associated morbidities and healthcare costs. It is a fact that conventional methods usually require more than 24–48 h to culture and profile bacterial species. Mass spectrometry (MS) is an analytical technique that has emerged as a powerful tool in clinical microbiology for identifying peptides and proteins, which makes it a promising tool for microbial identification. Matrix assisted laser desorption ionization–time of flight MS (MALDI–TOF MS) offers a cost- and time-effective alternative to conventional methods, such as bacterial culture and even 16S rRNA gene sequencing, for identifying viruses, bacteria and fungi and detecting virulence factors and mechanisms of resistance. This review provides an overview of the potential applications and perspectives of MS in clinical microbiology laboratories and proposes its use as a first-line method for microbial identification and diagnosis.

A Survey of Analytical Techniques for Noroviruses

As the leading cause of acute gastroenteritis worldwide, human noroviruses (HuNoVs) have caused around 685 million cases of infection and nearly $60 billion in losses every year. Despite their highly contagious nature, an effective vaccine for HuNoVs has yet to become commercially available. Therefore, rapid detection and subtyping of noroviruses is crucial for preventing viral spread. Over the past half century, there has been monumental progress in the development of techniques for the detection and analysis of noroviruses. However, currently no rapid, portable assays are available to detect and subtype infectious HuNoVs. The purpose of this review is to survey and present different analytical techniques for the detection and characterization of noroviruses.

New Microbiological Techniques in the Diagnosis of Bloodstream Infections

BACKGROUND

When a bloodstream infection is suspected, the preliminary and definitive results of culture-based microbiological testing arrive too late to have any influence on the initial choice of empirical antibiotic treatment.

METHODS

This review is based on pertinent publications retrieved by a selective search of the literature and on the authors' clinical and scientific experience.

RESULTS

A number of technical advances now enable more rapid microbiological diagnosis of bloodstream infections. DNA- based techniques for the direct detection of pathogenic organisms in whole blood have not yet become established in routine use because of various limitations. On the other hand, matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS) has become available for routine use in clinical laboratories and has markedly shortened the time to diagnosis after blood samples that have been cultured in automated blood-culture systems turn positive. Further developments of this technique now enable it to be used directly for blood cultures that have been flagged positive, as well as for subcultures that have been incubated for only a short time on a solid nutrient medium. The microbial biomass of the subculture can also be used in parallel for more rapid susceptibility testing with conventional methods, or, in future, with MALDI-TOF MS.

CONCLUSION

The potential of all of these new techniques will only be realizable in practice if they are optimally embedded in the diagnostic process and if sufficient attention is paid to pre-analytical issues, particularly storage and transport times.

Introduction into nanotechnology and microbiology

The current chapter summaries the world of Microbiology and boom of Nanotechnology and how both the exciting fields come together to help men kind with various new applications in water, food, medical biology and immunology. Furthermore synthesis of nano materials utilising the potential of microorganisms also opens a newer avenue for 'green' synthesis.

Overview of Trends in the Application of Metagenomic Techniques in the Analysis of Human Enteric Viral Diversity in Africa's Environmental Regimes

There has been an increase in the quest for metagenomics as an approach for the identification and study of the diversity of human viruses found in aquatic systems, both for their role as waterborne pathogens and as water quality indicators. In the last few years, environmental viral metagenomics has grown significantly and has enabled the identification, diversity and entire genome sequencing of viruses in environmental and clinical samples extensively. Prior to the arrival of metagenomics, traditional molecular procedures such as the polymerase chain reaction (PCR) and sequencing, were mostly used to identify and classify enteric viral species in different environmental milieu. After the advent of metagenomics, more detailed reports have emerged about the important waterborne viruses identified in wastewater treatment plant effluents and surface water. This paper provides a review of methods that have been used for the concentration, detection and identification of viral species from different environmental matrices. The review also takes into consideration where metagenomics has been explored in different African countries, as well as the limitations and challenges facing the approach. Procedures including sample processing, experimental design, sequencing technology, and bioinformatics analysis are discussed. The review concludes by summarising the current thinking and practices in the field and lays bare key issues that those venturing into this field need to consider and address.

Absolute quantification of norovirus capsid protein in food, water, and soil using synthetic peptides with electrospray and MALDI mass spectrometry

Norovirus infections are one of the most prominent public health problems of microbial origin in the U.S. and other industrialized countries. Surveillance is necessary to prevent secondary infection, confirm successful cleanup after outbreaks, and track the causative agent. Quantitative mass spectrometry, based on absolute quantitation with stable-isotope labeled peptides, is a promising tool for norovirus monitoring because of its speed, sensitivity, and robustness in the face of environmental inhibitors. In the current study, we present two new methods for the detection of the norovirus genogroup I capsid protein using electrospray and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The peptide TLDPIEVPLEDVR was used to quantify norovirus-like particles down to 500 attomoles with electrospray and 100 attomoles with MALDI. With MALDI, we also demonstrate a detection limit of 1 femtomole and a quantitative dynamic range of 5 orders of magnitude in the presence of an environmental matrix effect. Due to the rapid processing time and applicability to a wide range of environmental sample types (bacterial lysate, produce, milk, soil, and groundwater), mass spectrometry-based absolute quantitation has a strong potential for use in public health and environmental sciences.

Serum peptidome variations in a healthy population: reference to identify cancer-specific peptides

The emergence of mass spectrometry (MS)-based signatures as biomarkers has generated considerable enthusiasm among oncologists. However, variations in normal individuals also exist, and a better understanding of serum peptide patterns of healthy individuals will be important for further exploring disease-specific serum peptide patterns. Following development of a serum peptide pattern platform, we analyzed 500 serum samples obtained from healthy individuals. Samples from breast (n = 84), lung (n = 70), and rectal (n = 30) cancer patients were also examined. Extensive data analysis revealed negligible contributions of age to serum peptide patterns except in healthy individuals between 20–30 and 60+ years of age. Gender-related variations in the serum patterns of healthy individuals were only observed in 20–30 year-old individuals. Our results revealed substantial variation in individual peptide profiles, but 65 peptides were detected at a 20% higher frequency in the healthy population. A peptide profile was developed for each type of cancer, containing 10 discriminating peptides not prevalent in healthy individuals. Sequence identification of 111 signature peptides revealed that they fell into several tight clusters and most were exopeptidase products of serum resident proteins. We have obtained a MS-based serum peptide profile for healthy individuals, providing a reference for observing the occurrence of cancer-specific peptides.

MALDI TOF MS profiling of bacteria at the strain level: a review

Since the advent of the use of matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry (TOF MS) as a tool for microbial characterization, efforts to increase the taxonomic resolution of the approach have been made. The rapidity and efficacy of the approach have suggested applications in counter-bioterrorism, prevention of food contamination, and monitoring the spread of antibiotic-resistant bacteria. Strain-level resolution has been reported with diverse bacteria, using library-based and bioinformatics-enabled approaches. Three types of characterization at the strain level have been reported: strain categorization, strain differentiation, and strain identification. Efforts to enhance the library-based approach have involved sample pre-treatment and data reduction strategies. Bioinformatics approaches have leveraged the ever-increasing amount of publicly available genomic and proteomic data to attain strain-level characterization. Bioinformatics-enabled strategies have facilitated strain characterization via intact biomarker identification, bottom-up, and top-down approaches. Rigorous quantitative and advanced statistical analyses have fostered success at the strain level with both approaches. Library-based approaches can be limited by effects of sample preparation and culture conditions on reproducibility, whereas bioinformatics-enabled approaches are typically limited to bacteria, for which genetic and/or proteomic data are available. Biological molecules other than proteins produced in strain-specific manners, including lipids and lipopeptides, might represent other avenues by which strain-level resolution might be attained. Immunological and lectin-based chemistries have shown promise to enhance sensitivity and specificity. Whereas the limits of the taxonomic resolution of MALDI TOF MS profiling of bacteria appears bacterium-specific, recent data suggest that these limits might not yet have been reached.

[Mass spectrometry in the clinical microbiology laboratory]

Infectious diseases are still a cause of high mortality and morbidity rates. Current microbiological diagnostic methods are based on culture and phenotypic identification of isolated microorganisms, which can be obtained in about 24-48 h. Given that the microbiological identification is of major importance for patient management, new diagnostic methods are needed in order to detect and identify microorganisms in a timely and accurate manner. Over the last few years, several molecular techniques based on the amplification of microbial nucleic acids have been developed with the aim of reducing the time needed for the identification of the microorganisms involved in different infectious processes. On the other hand, mass spectrometry has emerged as a rapid and consistent alternative to conventional methods for microorganism identification. This review describes the most widely used mass spectrometry technologies -matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and electrospray ionization time-of-flight (ESI-TOF)-, both for protein and nucleic acid analysis, as well as the commercial platforms available. Related publications of most interest in clinical microbiology are also reviewed.

Norovirus diagnostics: options, applications and interpretations

Noroviruses are a frequent cause of both acute gastroenteritis and outbreaks of gastroenteritis. Infection is usually self-limiting although it has been associated with mortality in children in the developing world and in vulnerable groups such as immunodeficient or immunosuppressed and elderly patients elsewhere. Diagnostic tests may be useful in preventing or limiting the spread and duration of outbreaks, and are needed to define norovirus-associated morbidity and mortality. However, the interpretation of test results should take account of the limitations of the different tests currently available. Therefore, the clinical, immunological and molecular tests available for norovirus detection have been reviewed. Early recognition of cases (clinical diagnoses) together with confirmation by sensitive and specific laboratory tests may contribute to reducing the spread of norovirus within hospitals. Syndromic testing that includes multiple or multiplex assays for the detection of viral, bacterial and parasitic pathogens with the inclusion of control groups are likely to better define norovirus-associated morbidity and mortality in low- and middle-income countries.

Automating data acquisition affects mass spectrum quality and reproducibility during bacterial profiling using an intact cell sample preparation method with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

The use of matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry (TOF MS) has emerged as a promising tool to rapidly profile bacteria at the genus and species level and, more recently, at the sub-species (strain) level. Recently, it has been proposed that the approach can be enhanced with regard to reproducibility and throughput by automating spectrum acquisition; however, effects of automating spectrum acquisition on spectrum quality and reproducibility have not been investigated. Using an intact cell-based sample preparation method, we directly compared the quality and reproducibility of spectra acquired in a fully automated fashion to those acquired manually by two operators with different levels of experience. While automation tended to increase base peak resolution, other measures of spectrum quality, including signal-to-noise (S:N) ratio, data richness, and reproducibility were reduced. Negative effects of automation on the performance of this approach to bacterial profiling may be particularly important during profiling of closely related strains of bacteria that yield very similar spectra.

Multiplex reverse transcription PCR Luminex assay for detection and quantitation of viral agents of gastroenteritis

BACKGROUND

Several viruses can cause diarrheal disease, a leading cause of morbidity and mortality worldwide. Existing diagnostic methods include ELISA and nucleic acid amplification, usually performed individually.

OBJECTIVES

(1) To develop a multiplexed assay for simultaneous detection of major enteric viral pathogens. (2) Quantitation of viral load by normalizing with an extrinsic control.

STUDY DESIGN

A simple protocol combining a one-step multiplex reverse transcription-polymerase chain reaction (RT-PCR) with microsphere-based fluorescence detection was developed for norovirus GI and GII, rotavirus, astrovirus, sapovirus, and adenovirus. An extrinsic control, bacteriophage MS2, was spiked into each fecal sample before nucleic acid extraction to normalize between samples for the efficiency of nucleic acid extraction and amplification.

RESULTS

The fluorescent results were quantitative and nearly as sensitive as the corresponding singleplex real time RT-PCR (qRT-PCR) assay on analytic samples. Upon testing 229 fecal samples from inpatients with diarrhea in Tanzania the assay yielded between 88% and 100% sensitivity and specificity for all analytes. The difference in fluorescence intensities of MS2 between samples indicated variable extraction efficiency and was used to better refine the viral load of each specimen.

CONCLUSIONS

This one-step nucleic acid-based assay enables rapid, sensitive and specific detection of the major viral causes of gastroenteritis. The quantitation yielded by the assay is informative for clinical research particularly in the context of mixed infections.

MALDI-TOF-mass spectrometry applications in clinical microbiology

MALDI-TOF-mass spectrometry (MS) has been successfully adapted for the routine identification of microorganisms in clinical microbiology laboratories in the past 10 years. This revolutionary technique allows for easier and faster diagnosis of human pathogens than conventional phenotypic and molecular identification methods, with unquestionable reliability and cost–effectiveness. This article will review the application of MALDI-TOF-MS tools in routine clinical diagnosis, including the identification of bacteria at the species, subspecies, strain and lineage levels, and the identification of bacterial toxins and antibiotic-resistance type. We will also discuss the application of MALDI-TOF-MS tools in the identification of Archaea, eukaryotes and viruses. Pathogenic identification from colony-cultured, blood-cultured, urine and environmental samples is also reviewed.

Microbial fingerprinting using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) applications and challenges

Recent threats posed by pathogenic microorganisms in food, recreational waters, and as agents of bioterror have underscored the need for the development of more rapid, accurate, and cost-effective methods of microbial characterization and identification. This chapter focuses on the use of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to rapidly characterize and identify microorganisms through generation of characteristic fingerprints of intact cells. While most efforts have focused on bacteria, this technology has also been applied to fungi and viruses. Results of most studies suggest that MALDI-TOF MS can be used to rapidly and accurately characterize microorganisms. A variety of quantitative approaches have been employed in the analysis of MALDI-TOF MS fingerprints of microorganisms. The reproducibility of fingerprints of intact cells remains a primary concern and limitation associated with this approach. Protocols and instrumentation used have varied considerably and likely account for much of the variability in reproducibility reported. Key first steps to overcoming this limitation will be the development of standard approaches to quantifying reproducibility and the development of standard protocols for sample preparation and analysis.

Capsid and Infectivity in Virus Detection

The spectacular achievements and elegance of viral RNA analyses have somewhat obscured the importance of the capsid in transmission of viruses via food and water. The capsid's essential roles are protection of the RNA when the virion is outside the host cell and initiation of infection when the virion contacts a receptor on an appropriate host cell. Capsids of environmentally transmitted viruses are phenomenally durable. Fortuitous properties of the capsid include antigenicity, isoelectric point(s), sometimes hemagglutination, and perhaps others. These can potentially be used to characterize capsid changes that cause or accompany loss of viral infectivity and may be valuable in distinguishing native from inactivated virus when molecular detection methods are used.

The measurement of charge for induction-based fluidic MALDI dispense event and nanoliter volume verification in real time

This study preliminarily investigates whether nanoliter volumes of concentrated polar liquids and organic monomers launched to targets using induction based fluidics (IBF) can be verified through the real time charge measurements. We show that using a nanoliter IBF dispensing device and nanocoulomb meter, charge measurements made on nanoliter drops in real time are correlated with surface area following Gauss's Law. We infer the "induction only" formation of the double layer showing the ability to determine nanoliter volumes, nearly instantaneously, in real time. We discuss the implications that these observations may have for on improving/monitoring MALDI quantitation and its quality control.

Viral contaminants of molluscan shellfish: detection and characterisation

Environmental virology started with the detection of poliovirus in water. Since then other enteric viruses responsible for gastroenteritis and hepatitis have replaced enteroviruses as the main target for detection. Most shellfish-borne viral outbreaks are restricted to norovirus and hepatitis A virus, making them the main targets for bivalve virological analysis. The inclusion of virus analysis in regulatory standards for viruses in molluscan bivalve samples must overcome several shortcomings such as the technical difficulties and high costs of virus monitoring, the lack of harmonised and standardised assays and the challenge posed by the ever-changing nature of viruses. Nowadays methods are available to detect, quantify and characterise viral pathogens in molluscan shellfish to reduce the risks of shellfish-borne virus diseases.

Novel autoantigens in autoimmune hypophysitis

BACKGROUND

Pituitary autoantibodies are found in autoimmune hypophysitis and other conditions. They are a marker of pituitary autoimmunity but currently have limited clinical value. The methods used for their detection lack adequate sensitivity and specificity, mainly because the pathogenic pituitary autoantigen(s) are not known and therefore antigen-based immunoassays have not been developed.

OBJECTIVES

This study aimed to identify novel pituitary autoantigens using sera as probes in proteomic assays. We also compared immunoblotting and immunofluorescence methods for their accuracy in diagnosing autoimmune hypophysitis.

STUDY DESIGN AND SUBJECTS

Twenty-eight sera from autoimmune hypophysitis cases (14 histologically proven and 14 clinically suspected) were compared to 98 sera from controls, which included 14 patients with pituitary adenomas, 48 with autoimmune thyroiditis (15 Graves' disease and 33 Hashimoto's thyroiditis) and 36 healthy subjects.

METHODS

All sera were tested against human pituitary cytosolic proteins separated by one-dimensional (1D) gel electrophoresis. The band recognition was analysed statistically to detect molecular weight regions preferentially recognized by hypophysitis sera. 2D gel immunoblotting and mass spectrometry were then used to sequence the protein spots of interest. Sera were also tested by immunofluorescence for their recognition of Macaca mulatta pituitary sections.

RESULTS

A single region in the 25-27-kDa range was recognized more often by hypophysitis cases than healthy subjects (P = 0.004) or patients with pituitary adenomas (P = 0.044). This region contained two novel candidate autoantigens: chromosome 14 open reading frame 166 (C14orf166) and chorionic somatomammotrophin. Immunoblotting positivity for the 25-27-kDa region yielded greater sensitivity (64%vs. 57%) and specificity (86%vs. 76%) than immunofluorescence in predicting histologically proven hypophysitis, although the performance was still inadequate to make immunoblotting a clinically useful test.

CONCLUSION

The study reports two novel proteins that could act as autoantigens in autoimmune hypophysitis. Further studies are needed to validate their pathogenic role and diagnostic utility.

Autoimmune hypophysitis of SJL mice: clinical insights from a new animal model

Autoimmune hypophysitis (AH) is a rare but increasingly recognized disease of the pituitary gland. Its autoantigens are unknown, and the management is difficult because it is often misdiagnosed as a nonsecreting adenoma. By immunizing female SJL/J mice with mouse pituitary extracts, we established a new mouse model of experimental AH. Immunized mice developed severe lymphocytic infiltration in the anterior pituitary that closely mimicked the human pathology. In the early phase of experimental AH, the pituitary enlarged, consistent with the compression symptoms reported by hypophysitis patients at presentation. In the florid phase, adrenal insufficiency and pituitary antibodies developed, in strong correlation with the pituitary pathology. In the late phase, hypothyroidism ensued, and the pituitary gland became atrophic. Using immune sera as probes in a two-dimensional immunoblotting screen followed by mass spectrometry, we identified several proteins that could function as pituitary autoantigens. These findings provide new insights into the pathogenesis of AH, and establish a platform for developing novel diagnostic biomarkers and therapeutics.

Nanotechnology in proteomics

In genomics, the ability to amplify rare transcripts has enabled rapid advances in the understanding of gene expression patterns in human disease. The inability to increase the copy number and to detect the signal of rare proteins as unique species in biological samples has hindered the ability of proteomics to dissect human disease with the same complexity as genomic analyses. Advances in nanotechnology have begun to allow researchers to identify low-abundance proteins in samples through techniques that rely upon both nanoparticles and nanoscale devices. Coupled with rapid advances made in protein identification and isolation over the past decade, currently available technology enables more effective multiplexing and improved signal-to-noise, which enhances detection of low-abundance proteins in cellular and tissue lysates significantly. Techniques, including nanowires, nanocantilevers, bio-barcoding and surface-enhanced Raman spectroscopy, permit the detection of proteins into the low attomolar range, where many biologically important cellular processes occur. In this review, we summarize several such techniques, highlight their implementation in current protein research and comment on their potential role in future proteomic investigations and biomedical applications.

Current literature in mass spectrometry

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of mass spectrometry. Each bibliography is divided into 11 sections: 1 Books, Reviews & Symposia; 2 Instrumental Techniques & Methods; 3 Gas Phase Ion Chemistry; 4 Biology/Biochemistry: Amino Acids, Peptides & Proteins; Carbohydrates; Lipids; Nucleic Acids; 5 Pharmacology/Toxicology; 6 Natural Products; 7 Analysis of Organic Compounds; 8 Analysis of Inorganics/Organometallics; 9 Surface Analysis; 10 Environmental Analysis; 11 Elemental Analysis. Within each section, articles are listed in alphabetical order with respect to author (6 Weeks journals ‐ Search completed at 4th. Oct. 2006)