Frequently asked questions
How much does the analysis cost per sample?
The analytical cost is calculated individually for each project. The price of the analysis consists of two parts, the wet chemistry (sample preparation, liquid chromatography in reversed phase and hilic chromatographies, mass spectrometry in qTOF electrospray ionization in positive and negative mode), and the data-analytical part (data collection, data preprocessing, statistical analysis, and compound identification). The cost for the wet chemistry for a sample depends on the sample type and total number of samples, whereas the data analysis depends on the project/study design and your goals. Please contact us if you need help with planning a suitable project for your needs. Please also contact us to get estimate/quote for your project.
What is your method most suitable for?
As long as there is a set of biological samples with at least two groups and minimum three replicates (e.g., control and treatment), we can analyse the metabolites and do comparison between the groups. It is also possible to do completely exploratory analysis from individual samples without comparison (i.e. what kind of metabolites can be found within a certain sample). Our method is suitable for all biofluids, tissues, plants, food, whole insects, cell cultures, intestinal contents, etc.
How many compounds can you identify?
The composition of metabolites in each analysis depends on various factors, including the sample type, sampling protocol, extraction procedure, and ionization efficiency of the compounds. There are various compound classes that are routinely detected in our analyses e.g. amino acids, acylcarnitines, various lipid species, bile acids, phytochemicals and compounds produced by the microbiota. However, we do not restrict the analysis solely to the compounds we have detected earlier, and therefore the non-targeted metabolite profiling allows finding novel compounds and non-hypothesized phenomena in the metabolite composition. We analyze the samples with four different analytical modes to maximize the metabolite coverage and therefore the number of metabolite signals typically detected is several thousands. Currently our private database contains over a thousand compounds, and is being constantly updated. In addition, we use public databases and different computational algorithms to help identify compound structures.
Is there something your method cannot do?
Because of the wide-scale nature of the analysis, single compounds will be measured as relative levels instead of concentration (e.g. mg/L), still allowing full comparison between samples. Large macromolecules, such as peptides above 1500 Da, proteins, DNA, and complex carbohydrates, will be eliminated in the sample preparation and are not in the scope of metabolomics analyses.
What about the unknown compounds?
You may have heard that one of the biggest obstacles in metabolic profiling is that most of the detected compounds are unidentifiable. This is true to some extent. The technological advancements in the field of mass spectrometry have gone forward much faster than the identification databases. This is mainly because the current technologies can detect massive amounts of different metabolites with a single analysis run. Our team has a long experience in exploring novel compounds emerging from metabolomics analyses, and as we love to explore the compound spectra, we are putting in all of our scientific knowledge and knowhow to identify also these previously unknown compounds. In particular, we are experts in identifying phytochemicals that are present as several thousands of compounds in any plant or plant-based food, and for which there are no commercial standards available. In cases where identifying an interesting compound is not currently feasible, we still report the spectral features for that compound, and therefore enable later identification.
Do I need control samples?
Yes. The non-targeted metabolite profiling approach is a semi-quantitative measurement, where metabolite signals are compared between samples or different study groups, and the signals showing a significant difference in the statistical and chemometrical analysis are identified in detail. In non-targeted metabolite profiling experiment, it is important that the control samples are from same/similar sample matrices, from as similar as possible conditions, and collected with the same sampling procedure. These issues should be taken into account when planning the experiments, and we can help in the process.
How much sample material should I send?
We typically use 100 μL of biofluids (plasma, serum, urine, saliva), but in case of restricted sample availability (e.g. mouse plasma) working with smaller amount is possible (50 μL). The amount of tissue samples should be at least 50 mg, and the number of cells in cell culture assays about one million.
What is the difference between MS and NMR based metabolomics analysis?
The key difference is the sensitivity. mass spectrometry (MS) is several orders of magnitude more sensitive than nuclear magnetic resonance (NMR). In NMR-based metabolomics analyses of, for example human plasma the measurement covers typically 200-300 predefined compounds present in the sample in high concentrations. In MS-based metabolic profiling analysis, all the chemical signals resulting from thousands of compounds present in the sample are taken into account in the analysis. With the MS approach, much wider repertoire of compounds, including also unknown compounds and compounds with low concentrations, are included in the analysis. The two approaches are mostly complementary, as there are also compounds that can be better detected with NMR.