Tomas Cajka

University of California, Davis | UCD · UC Davis Genome Center

Liquid chromatography with mass spectrometry (LC-MS)-based metabolomics detects thousands of molecular features (retention time–m/z pairs) in biological samples per analysis, yet the metabolite annotation rate remains low, with 90% of signals classified as unknowns. To enhance the metabolite annotation rates, researchers employ tandem mass spectral...

Styrene-maleic acid (SMA) and similar amphiphilic copolymers are known to cut biological membranes into lipid nanoparticles/nanodiscs containing membrane proteins apparently in their relatively native membrane lipid environment. Our previous work demonstrated that membrane raft microdomains resist such disintegration by SMA. The use of SMA in study...

Despite intensive preventive cardiovascular disease (CVD) efforts, substantial residual CVD risk remains even for individuals receiving all guideline-recommended interventions. Niacin is an essential micronutrient fortified in food staples, but its role in CVD is not well understood. In this study, untargeted metabolomics analysis of fasting plasma...

Metabolic syndrome is a growing concern in developed societies, and due to its polygenic nature, the genetic component is only slowly being elucidated. Common mitochondrial DNA sequence variants have been associated with symptoms of metabolic syndrome and may be relevant players in the genetics of metabolic syndrome. We investigate the effect of mi...

p -Cresol sulfate ( p CS) and indoxyl sulfate (IS), gut microbiome-derived metabolites, are traditionally associated with cardiovascular disease (CVD) risks in the setting of impaired kidney function. While pharmacologic provision of p CS or IS can promote pro-thrombotic phenotypes, neither the microbial enzymes involved nor direct gut microbial pr...

Obesity adversely affects bone and fat metabolism in mice and humans. Omega-3 polyunsaturated fatty acids (omega-3 PUFAs) have been shown to improve glucose metabolism and bone homeostasis in obesity. However, the impact of omega-3 PUFAs on bone marrow adipose tissue (BMAT) and bone marrow stromal cell (BMSC) metabolism has not been intensively stu...

Background: Bone marrow stromal cells (BMSCs) are the source of multipotent stem cells, which are important for regenerative medicine and diagnostic purposes. The isolation of human BMSCs from the bone marrow (BM) cavity using BM aspiration applies the method with collection into tubes containing anticoagulants. Interactions with anticoagulants may...

Liquid chromatography-mass spectrometry (LC-MS) is the key technique for analyzing complex lipids in biological samples. Various LC-MS modes are used for lipid separation, including different stationary phases, mobile-phase solvents, and modifiers. Quality control in lipidomics analysis is crucial to ensuring the generated data's reliability, repro...

Introduction Non-alcoholic fatty liver disease (NAFLD) can progress to more severe stages, such as steatohepatitis and fibrosis. Thermoneutral housing together with high-fat diet promoted NAFLD progression in C57BL/6J mice. Due to possible differences in steatohepatitis development between different C57BL/6 substrains, we examined how thermoneutral...

The exact mechanisms behind cardioprotective effects of SGLT-2 inhibitors (SGLT-2i) are still not fully elucidated. Using complex transcriptomic, metabolomic and immunochemical methods we analysed epicardial (EAT) and subcutaneous (SAT) adipose tissue of patients with severe heart failure treated with SGLT-2i in order to identify possible cardiopro...

Thermal reactions can significantly alter the metabolomic and lipidomic content of biofluids and tissues during storage. In this study, we investigated the stability of polar metabolites and complex lipids in dry human serum and mouse liver extracts over a three-day period under various temperature conditions. Specifically, we tested temperatures o...

An advantageous alternative to the use of detergents in biochemical studies on membrane proteins are the recently developed styrene-maleic acid (SMA) amphipathic copolymers. In our recent study [1] we demonstrated that using this approach, most T cell membrane proteins were fully solubilized (presumably in small nanodiscs), while two types of raft...

Bis(monoacylglycero)phosphates (BMPs), a class of lipids highly enriched within endolysosomal organelles, are key components of the lysosomal intraluminal vesicles responsible for activating sphingolipid catabolic enzymes. While BMPs are understudied relative to other phospholipids, recent reports associate BMP dysregulation with a variety of patho...

Objective: Non-shivering thermogenesis (NST) mediated by uncoupling protein 1 (UCP1) in brown adipose tissue (BAT) can be activated via the adrenergic system in response to cold or diet, contributing to both thermal and energy homeostasis. Other mechanisms, including metabolism of skeletal muscle, may also be involved in NST. However, relative con...

Liquid chromatography-mass spectrometry (LC-MS) is the method of choice for the untargeted profiling of biological samples. A multiplatform LC-MS-based approach is needed to screen polar metabolites and lipids comprehensively. Different mobile phase modifiers were tested to improve the electrospray ionization process during metabolomic and lipidomi...

Edible mushrooms are consumed worldwide. The overall amount of lipids in mushrooms is small and consists of complex lipids, such as triacylglycerols, phospholipids, and sterols. Nutritional studies have outlined the lipid compositions of mushrooms but have not analyzed their fatty acid esters of hydroxy fatty acid (FAHFA) profiles. FAHFAs are a cla...

Current metabolomics and lipidomics studies are limited in the number of examined matrices, the breadth and scope of methods, reporting the number of metabolites, and data sharing. Here, we discuss the concept of metabolomics and lipidomics atlases that characterize the quantitative distribution and relationships of metabolites in biological matric...

We review the current analytical methods for analyzing type 2 diabetes (T2D) medication in human and animal samples. We discuss the advantages and limitations during sample preparation, separation, and detection of these drugs. Finally, we highlight the parameters to be considered for multi-targeted analytical methods and for assessing T2D medicati...

Peroxiredoxin 6 (Prdx6) is a multifunctional enzyme, a unique member of the peroxiredoxin family, with an important role in antioxidant defense. Moreover, it has also been linked with the biosynthesis of anti-inflammatory and anti-diabetic lipids called fatty acid esters of hydroxy fatty acids (FAHFAs) and many diseases, including cancer, inflammat...

Objective The use of thiazolidinediones (TZDs) as insulin sensitizers has been shown to have side effects including increased accumulation of bone marrow adipocytes (BMAds) associated with a higher fracture risk and bone loss. A novel TZD analog MSDC-0602K with low affinity to PPARγ has been developed to reduce adverse effects of TZD therapy. Howev...

The exact mechanisms behind favorable metabolic and cardioprotective effects of SGLT-2 inhibitors (SGLT-2i) are still not fully understood. We performed a complex metabolomic analysis of subcutaneous (SAT) and epicardial (EAT) adipose tissue of heart failure subjects treated with SGLT-2i in order to assess their impact on different fat depots and i...

Breast milk is a complex mixture containing underexplored bioactive lipids. We performed an observational case-control study to compare the impact of delivery mode: caesarean section (CS) and vaginal birth (VB); and term (preterm and term delivery) on the levels of lipokines in human milk at different stages of lactation. Metabolomic analysis of th...

Glucose tolerance represents a complex phenotype in which many tissues play important roles and interact to regulate metabolic homeostasis. Here, we perform an analysis of 13C6-glucose tissue distribution, which maps the metabolome and lipidome across 12 metabolically relevant mouse organs and plasma, with integrated 13C6-glucose-derived carbon tra...

Preclinical evidence suggests that n-3 fatty acids EPA and DHA (Omega-3) supplemented as phospholipids (PLs) may be more effective than triacylglycerols (TAGs) in reducing hepatic steatosis. To further test the ability of Omega-3 PLs to alleviate liver steatosis, we used a model of exacerbated non-alcoholic fatty liver disease based on high-fat fee...

Significance Fat mass is controlled by the balance of triacylglycerol (TAG) degradation and synthesis. Adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) are key players in TAG catabolism providing fatty acids (FAs) as energy substrates and metabolic intermediates. Here, we show that ATGL and HSL metabolize TAGs containing antidi...

Long-chain n-3 polyunsaturated fatty acids (Omega-3) and anti-diabetic drugs thiazolidinediones (TZDs) exhibit additive effects in counteraction of dietary obesity and associated metabolic dysfunctions in mice. The underlying mechanisms need to be clarified. Here, we aimed to learn whether the futile cycle based on the hydrolysis of triacylglycerol...

Background Cachexia worsens long‐term prognosis of patients with heart failure (HF). Effective treatment of cachexia is missing. We seek to characterize mechanisms of cachexia in adipose tissue, which could serve as novel targets for the treatment. Methods The study was conducted in advanced HF patients (n = 52; 83% male patients) undergoing heart...

We present Mass Spectrometry-Data Independent Analysis software version 4 (MS-DIAL 4), a comprehensive lipidome atlas with retention time, collision cross-section and tandem mass spectrometry information. We formulated mass spectral fragmentations of lipids across 117 lipid subclasses and included ion mobility tandem mass spectrometry. Using human,...

Scope Docosahexaenoic acid ester of hydroxy linoleic acid (DHAHLA) is a bioactive lipids with anti‐inflammatory properties from the family of fatty acid esters of hydroxy fatty acids (FAHFA). Methods and results To explore the biosynthesis of 13‐DHAHLA from dietary oils, C57BL/6N mice were gavaged for 8 days with various corn oil / marine oil mixt...

Using untargeted metabolomics (n = 1,162 subjects), the plasma metabolite (m/z = 265.1188) phenylacetylglutamine (PAGln) was discovered and then shown in an independent cohort (n = 4,000 subjects) to be associated with cardiovascular disease (CVD) and incident major adverse cardiovascular events (myocardial infarction, stroke, or death). A gut micr...

To the Editor We formulated mass spectral fragmentations of lipids across 117 lipid subclasses and included ion mobility tandem mass spectrometry (MS/MS) to provide a comprehensive lipidome atlas with retention time, collision cross section, and MS/MS information. The all-in-one solution from import of raw MS data to export of a common output forma...

Branched esters of palmitic acid and hydroxy-stearic acid (PAHSA) are anti-inflammatory and anti-diabetic lipokines that connect glucose and lipid metabolism. We aimed to characterize involvement of the 5-PAHSA regioisomer in the adaptive metabolic response of white adipose tissue (WAT) to cold exposure (CE) in mice, exploring the crosstalk between...

Adverse effects of aging can be delayed with life-style interventions. We examined how exercise training (ET) alone or combined with omega-3 polyunsaturated fatty acid (PUFA) affects serum and adipose tissue (AT) lipidome in older women. Fifty-five sedentary older women were included in the physical activity program and given either sunflower (Plac...

Biological sex is one of the major anthropometric factors which influences physiology, metabolism and health status. We have investigated the effect of sexual dimorphism on the blood lipidome profile in three large population level studies - the Alzheimer disease neuroimaging initiative - ADNI (n =806), the GeneBank Functional Cardio-Metabolomics c...

Mass spectrometry raw data repositories, including Metabolomics Workbench and MetaboLights, have contributed to increased transparency in metabolomics studies and the discovery of novel insights in biology by reanalysis with updated computational metabolomics tools. Herein, we reanalyzed the previously published lipidomics data from nine algal spec...

Oleaginous microbes, which contain over 20% intracellular lipid, predominantly triacylglycerols (TG), by dry weight, have been discovered to have high oil content by many different protocols, ranging from simple staining to more complex chromatographic methods. In our laboratory, a methodical process was implemented to identify high oil yeasts, des...

Large-scale untargeted lipidomics experiments involve the measurement of hundreds to thousands of samples. Such data sets are usually acquired on one instrument over days or weeks of analysis time. Such extensive data acquisition processes introduce a variety of systematic errors, including batch differences, longitudinal drifts or even instrument-...

Alzheimer’s disease (AD) is a major public health priority with a large socioeconomic burden and complex etiology. The Alzheimer Disease Metabolomics Consortium (ADMC) and the Alzheimer Disease Neuroimaging Initiative (ADNI) aim to gain new biological insights in the disease etiology. We report here an untargeted lipidomics of serum specimens of 80...

An emerging alternative to the use of detergents in biochemical studies on membrane proteins is apparently the use styrene-maleic acid (SMA) amphipathic copolymers. These cut the membrane into nanodiscs (SMA-lipid particles, SMALPs), which contain membrane proteins possibly surrounded by their native lipid environment. We examined this approach for...

Neuropeptides are short peptides in the range of 3–40 residues that are secreted for cell-cell communication in neuroendocrine systems. In the nervous system, neuropeptides comprise the largest group of neurotransmitters. In the endocrine system, neuropeptides function as peptide hormones to coordinate intercellular signaling among target physiolog...

Using an untargeted metabolomics approach in initial (N = 99 subjects) and replication cohorts (N = 1,162), we discovered and structurally identified a plasma metabolite associated with cardiovascular disease (CVD) risks, N6,N6,N6-trimethyl-L-lysine (trimethyllysine, TML). Stable-isotope-dilution tandem mass spectrometry analyses of an independent...

Acrylamide represents toxic compound presence of which in heat processed foodstuffs has been proven only recently. This chemical is of a great health concern since it is classified as a human carcinogen by the International Agency for Research on Cancer (IARC). Relatively high amounts of acrylamide have been found mainly in starch rich foods such a...

Obesity and accompanying metabolic disease is negatively correlated with lung health yet the exact mechanisms by which obesity affects the lung are not well characterized. Since obesity is associated with lung diseases as chronic bronchitis and asthma, we designed a series of experiments to measure changes in lung metabolism in mice fed obesogenic...

Principle component analysis (PCA) of HILIC and RPLC-QTOFMS metabolite data of lung, liver and kidney tissues. (TIF)

Orthogonal partial least square discriminant analysis (OPLSDA) of HILIC and RPLC-QTOFMS metabolite data of lung, liver and kidney tissues. Validation statistics by100 rounds of Monte Carlo permutation testing and for A: Lung Q2 = 0.0495, RSMEP = 0.0198, B: Liver Q2 = 0.0099, RSMEP = 0.0198 and C: Kidney Q2 = 0.0099, RSMEP = 0.0198. (TIF)

Compound IDs, student’s t-test results and fold change for all annotated compounds. (XLSX)

Orthogonal partial least square discriminant analysis (OPLSDA) of GC-TOFMS metabolite data of lung, liver and kidney tissues. Validation statistics by100 rounds of Monte Carlo permutation testing and for A: Lung Q2 = 0.2673, RSMEP = 0.0396, B: Liver Q2 = 0.0693, RSMEP = 0.1089 and C: Kidney Q2 = 0.2970, RSMEP = 0.1386. (TIF)

Principle component analysis (PCA) of GC-TOFMS metabolite data of lung, liver and kidney tissues. (TIF)

Extracellular fungal glycolipid biosurfactants have attracted attention because productivities can be high, cheap substrates can be used, the molecules are secreted into the medium and the downstream processing is relatively simple. Three classes of extracellular fungal glycolipid biosurfactants have provided most of the scientific advances in this...

Provided are methods and yeast cultures for producing polyol lipids and polyol lipid compositions. (https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2017184884&recNum=1&maxRec=&office=&prevFilter=&sortOption=&queryString=&tab=PCT+Biblio)

Liquid chromatography–mass spectrometry (LC–MS) methods are most often used for untargeted metabolomics and lipidomics. However, methods have not been standardized as accepted ‘best practice’ documents, and reports lack harmonization with respect to quantitative data that enable inter-study comparisons. Researchers use a wide variety of high-resolu...

As the lipidomics field continues to advance, self-evaluation within the community is critical. Here, we performed an interlaboratory comparison exercise for lipidomics using Standard Reference Material (SRM) 1950 Metabolites in Frozen Human Plasma, a commercially available reference material. The interlaboratory study comprised 31 diverse laborato...

Nonalcoholic fatty liver disease (NAFLD) in non-obese patients remains a clinical condition with unclear etiology and pathogenesis. Using a metabolomics approach in a mouse model that recapitulates almost all the characteristic features of non-obese NAFLD, we aimed to advance mechanistic understanding of this disorder. Mice fed high fat, high chole...

Microbial oils have been analyzed as alternatives to petroleum. However, just a handful of microbes have been successfully adapted to produce chemicals that can compete with their petroleum counterparts. One of the reasons behind the low success rate is the overall economic inefficiency of valorizing a single product. This study presents a lab-scal...

This protocol describes the analysis, specifically the identification, of blood plasma lipids. Plasma lipids are extracted using methyl tert-butyl ether (MTBE), methanol, and water followed by separation and data acquisition of isolated lipids using reversed-phase liquid chromatography coupled to quadrupole/time-of-flight mass spectrometry (RPLC–QT...

In 2016, as part of the Reproducibility Project: Cancer Biology, we published a Registered Report (Fiehn et al., 2016), that described how we intended to replicate selected experiments from the paper "The common feature of leukemia-associated IDH1 and IDH2 mutations is a neomorphic enzyme activity converting alpha-ketoglutarate to 2-hydroxyglutarat...

COX metabolites of 8,9-EET, previously observed as potent mitogenic lipid mediators, were synthesized for the first time by using two synthetic approaches. These synthetic materials allow for structural confirmation of COX metabolites of 8,9-EET and further study of their biological roles.

Tandem mass spectral library search (MS/MS) is the fastest way to correctly annotate MS/MS spectra from screening small molecules in fields such as environmental analysis, drug screening, lipid analysis, and metabolomics. The confidence in MS/MS-based annotation of chemical structures is impacted by instrumental settings and requirements, data acqu...

Significance This study furthers our understanding of epoxyeicosatrienoic acid metabolism by cyclooxygenase (COX) enzymes as a physiologically relevant metabolic pathway, producing signaling molecules that are angiogenic. It explains, in part, why inhibiting the soluble epoxide hydrolase (sEH) in some systems is angiogenic whereas combining sEH inh...

There is a need for fast detection methods for the banned rodenticide tetramethylenedisulfotetramine (TETS), a highly potent blocker of the γ-aminobutyric acid (GABAA) receptors. General synthetic approach toward two groups of analogues was developed. Screening of the resulting library of compounds by FLIPR or whole-cell voltage-clamp revealed that...

Polyol esters of fatty acids (PEFA) are amphiphilic glycolipids produced by yeast that could play a role as natural, environmentally friendly biosurfactants. We recently reported discovery of a new PEFA-secreting yeast species, Rhodotorula babjevae, a basidiomycetous yeast to display this behavior, in addition to a few other Rhodotorula yeasts repo...

Untargeted metabolomics by liquid chromatography–mass spectrometry generates data-rich chromatograms in the form of m/z-retention time features. Managing such datasets is a bottleneck. Many popular data processing tools, including XCMS-online and MZmine2, yield numerous false-positive peak detections. Flagging and removing such false peaks manually...

Enzymatic transformations of primary, canonical metabolites generate active biomolecules that regulate important cellular and physiological processes. Roles include regulation of histone demethylation in epigenetics, inflammation in tissue injury, insulin sensitivity, cancer cell invasion, stem cell pluripotency status, inhibition of nitric oxide s...

A multiplatform mass spectrometry-based approach was used for elucidating extracellular lipids with biosurfactant properties produced by the oleaginous yeast Rhodotorula babjevae UCDFST 04-877. This strain secreted 8.6 ± 0.1 g/L extracellular lipids when grown in a benchtop bioreactor fed with 100 g/L glucose in medium without addition of hydrophob...

Recent advances in mass spectrometry have led to the development of novel methods applicable in food chemistry and technology. Specifically, mass spectrometry-based omics sciences have introduced high-throughput methods permitting complex assessment of food authenticity and detection of adulteration. In this chapter, we focus mainly on mass spectro...

Compound identification from accurate mass MS/MS spectra is a bottleneck for untargeted metabolomics. In this study, we propose nine rules of hydrogen rearrangement (HR) during bond cleavages in low-energy collision-induced dissociation (CID). These rules are based on the classic even-electron rule and cover heteroatoms and multi-stage fragmentatio...

Introduction Plasma fatty acids are derived from preformed sources in the diet and de novo synthesis through the action of desaturase and elongase enzymes. Objective This study was designed to examine the elongation of gamma-linolenic acid (GLA, 18:3n6) into dihomo-gamma-linolenic acid (DGLA, 20:3n6) over an 8-h period using both targeted gas chrom...

Introduction—Plasma fatty acids are derived from preformed sources in the diet and de novo synthesis through the action of desaturase and elongase enzymes. Objective—This study was designed to examine the elongation of gamma-linolenic acid (GLA, 18:3n6) into dihomo-gamma-linolenic acid (DGLA, 20:3n6) over an 8-h period using both targeted gas chrom...

Of 1600 known species of yeasts, about 70 are known to be oleaginous, defined as being able to accumulate over 20 % intracellular lipids. These yeasts have value for fundamental and applied research. A survey of yeasts from the Phaff Yeast Culture Collection, University of California Davis was performed to identify additional oleaginous species wit...

Reversed-phase ultrahigh-performance liquid chromatography–mass spectrometry (UHPLC–MS) is the method of choice for lipidomic profiling of blood plasma. For comprehensive screening, lipids need to be screened in both positive and negative electrospray mode. We here show that optimal results for increased lipidome coverage are only obtained if two d...

In this review, we discuss whether novel techniques in mass spectrometry, from ultrahigh resolution detection to data-independent MS/MS and ion mobility methods, have advanced so far that selectivity and sensitivity of untargeted analyses have indeed reached a point at which hypothesis-driven validation studies can be conducted by accurate mass pro...

Applications of PeakInvestigator mass spectral centroiding software.

Application of PeakInvestigator mass spectral centroiding software.

Data-independent acquisition (DIA) in liquid chromatography (LC) coupled to tandem mass spectrometry (MS/MS) provides comprehensive untargeted acquisition of molecular data. We provide an open-source software pipeline, which we call MS-DIAL, for DIA-based identification and quantification of small molecules by mass spectral deconvolution. For a rev...

Liquid chromatography-mass spectrometry (LC-MS)-based lipidomics has undergone dramatic developments over the past decade. This review focuses on state of the art in LC-MS-based lipidomics, covering all the steps of global lipidomic profiling. By reviewing 185 original papers and application notes, we can conclude that current advanced LC-MS-based...

Mycotoxins represent an important natural contaminants of food and feed. Because of their toxicity and widespread occurrence, great attention is paid to the development and validation of rapid and reliable analytical methods for detection and quantification of mycotoxins. In this chapter, topics relevant to high-throughput analysis of mycotoxins in...

Mass spectrometry (MS) and hyphenated chromatographic techniques have been subjects of dramatic developments, resulting in the introduction of newer tools for the detection and quantitation of diverse analytes in a range of matrices. In addition to these chromatography-based approaches, a large number of novel direct MS techniques have become avail...

Data-independent MS/MS approaches such as SWATH, MSE, or all ion fragmentation are much richer in information content compared to classic data-dependent MS/MS experiments. We have developed novel GUI-based software to identify far more metabolites using adduct speciation, spectral de-convolution and library comparisons. The software exploits two ax...

Description of new mass spectrometry centroiding software based on a new statistically-valid algorithmic method.

Ultra high performance liquid chromatography with quadrupole/time-of-flight mass spectrometry was applied to evaluate the potential of nontarget metabolomic fingerprinting in order to distinguish Fusarium-infected and control barley samples. First, the sample extraction and instrumental conditions were optimized to obtain the broadest possible repr...

Ambient mass spectrometry employing a direct analysis in real time (DART) ion source coupled to a medium high-resolution/accurate mass time-of-flight mass spectrometer (TOFMS) was used as a rapid tool for metabolomic fingerprinting to study the effects of supplemental feeding with cereals (triticale) on the composition of muscle metabolites of comm...

This chapter provides a general overview of gas chromatography (GC)–time-of-flight mass spectrometry basic features, highlighting its advantages and limitations compared to GC using conventional mass analyzers. Examples of results obtained for food and environmental contaminants, aroma and flavor components, and food authenticity assessment are des...

Instability and tendency to oxidation depending to conditions is a dominant property of hop beta acids. Mentioned property has an impact both on hop storage and beer brewing process. Approximately half amount decomposes at room temperature under open air conditions in the course of one month. After 6 months the rate of degradation is more than 90%....

A new method for rapid determination of 73 target organic environmental contaminants including 18 polychlorinated biphenyls, 16 organochlorinated pesticides, 14 brominated flame retardants and 25 polycyclic aromatic hydrocarbons in fish and fish feed using gas chromatography coupled with triple quadrupole tandem mass spectrometry (GC-MS/MS) was dev...

In this study, gas chromatography (GC) coupled to triple quadrupole tandem mass spectrometry (MS/MS) operated in electron ionisation mode (EI) has been shown to be an effective tool for the (ultra)trace analysis of several representative brominated flame retardants (BFRs) including polybrominated diphenyl ethers (PBDEs), pentabromotoluene (PBT), pe...

Metabolomic fingerprinting enabled by ambient mass spectrometry employing a direct analysis in real time (DART) ion source coupled to a medium–high resolution/accurate mass time-of-flight mass spectrometer (TOFMS) was used as a tool for differentiation between chickens fed by feed that contained 5–8 % (w/w) of chicken bone meal (a banned component)...