Abstract: The invention relates to the detection of specified, flagellated bacteria, particularly Salmonella, in food and stool. A single culturing period of about 12 to 24 hours in a liquid nutrient medium without agitation is combined with a position-selective sampling of the flagellated microbes from the liquid of the culture, after which a mass spectrometric detection method is used which recognizes the target bacteria in mixtures. A second culture step is only necessary in exceptional cases. A species-selective or genus-selective culture medium is advantageous. Positional selection becomes possible because these bacteria use their flagella to counteract sedimentation by chemotaxis, and they collect near the surface.

Abstract: The invention relates to the determination of the nature and strength of enzymatic activity in blood using mass spectrometric measurement of a profile of the reaction products. The determination of the enzymatic activity can be used for medical diagnostics, for example, and also to check the effectiveness of medication. The invention provides a method whereby adding probe substances usually not present in blood offers standardized substrates for measuring the enzymatic activity. The probe substances may be added to whole blood, plasma, or serum. The mass spectrometric measurement of the reaction products, after their reversible immobilization on actively binding surfaces of solids, for example, can deliver biomarker patterns of the reaction products which may be indicators for metabolic anomalies or diseases, since these are often accompanied by the formation or activation of characteristic enzymes.

Abstract: The invention relates to acquisition techniques for time-of-flight mass spectra with ionization of the analyte substances by matrix assisted laser desorption. Generally speaking, these acquisition techniques involve adding together a large number of individual time-of-flight spectra, each with restricted dynamic measuring range, to form a sum spectrum. The invention provides a method that improves, in particular, the reproducibility, the concentration accuracy and therefore the ability to quantify the mass spectra. Particular embodiments also increase the dynamic range of measurement. For this purpose, multiple series of mass spectra are acquired, whereby the energy density in the laser spot is increased in discrete steps. As a result, many ion signals saturate the detector and can therefore no longer be evaluated.

Abstract: A method of detecting specified target microbes in different types of sample uses only one to two cultivation steps for the enrichment of the target microbes from the sample, preferably in selective culture media, combined with a mass spectrometric detection method that identifies the target microbes in mixtures with other microbes even if the target microbes account for only a small proportion of the mixture. The sample may be a food sample, a sample from bodies of water used for bathing, a soil sample, a swabbed sample, a stool sample, an impactor sample with collected aerosol particles, amongst many others. The detection method is several days faster than standard methods and less expensive.

Abstract: Microbes in a sample are identified by calculating similarities between a mass spectrum of the sample and reference mass spectra in a spectral library. The spectral library is divided into a hierarchy of sub-libraries where each sub-library contains reference mass spectra of microbes which are statistically the most prevalent in the samples, but are not included in other sub-libraries and all additional reference mass spectra in the library that have substantial similarity to the reference mass spectra of these microbes. Only if the search in a sub-library does not provide a hit with sufficient certainty of identification, is the search carried out in sub-libraries of higher stages.

Abstract: A dual-stage method is provided for identifying a microbe by, for example, its species or its subspecies. The method includes measuring a mass spectrum of the microbe using a mass spectrometer, calculating indicators for similarities between reference mass spectra in a library and the measured mass spectrum, selecting a group of reference mass spectra similar to the measured mass spectrum, determining a distinguishing weight for each mass signal of the reference mass spectra in the group, where the distinguishing weights emphasize differences between the reference mass spectra in the group, and calculating indicators for similarities between the reference mass spectra in the group and the measured mass spectrum as a function of the distinguishing weights.

Abstract: Microorganisms are identified as present in a complex sample or mixed culture by acquiring a mass spectrum of the sample and comparing it to combination spectra, each of which is formed by combining at least two reference mass spectra of known microorganisms. Microorganisms corresponding to the reference spectra used to form the combination spectrum are identified as present in the sample if that combination spectrum exhibits a better match with the sample mass spectrum than any one of reference mass spectra used to form that combination spectrum. It is also possible to identify microorganisms by forming a difference spectrum by subtracting a reference mass spectrum from the sample mass spectrum and comparing the difference spectrum to the reference mass spectra.

Abstract: The invention relates to the determination of the nature and strength of enzymatic activity in blood using mass spectrometric measurement of a profile of the reaction products. The determination of the enzymatic activity can be used for medical diagnostics, for example, and also to check the effectiveness of medication. The invention provides a method whereby adding probe substances usually not present in blood offers standardized substrates for measuring the enzymatic activity. The probe substances may be added to whole blood, plasma, or serum. The mass spectrometric measurement of the reaction products, after their reversible immobilization on actively binding surfaces of solids, for example, can deliver biomarker patterns of the reaction products which may be indicators for metabolic anomalies or diseases, since these are often accompanied by the formation or activation of characteristic enzymes.

Abstract: The invention generates mass scale comparability between mass spectra which are acquired in time-of-flight mass spectrometers, particularly with ionization by matrix-assisted laser desorption. Always slightly distorted mass scales of different mass spectra from the same type of sample can be aligned. The flight times of identical ions always differ slightly from one mass spectrum to the next due to non-reproducible processes in the ionization method. Thus the apparent mass values of ion signals of identical substances in different mass spectra do not match even if the flight times are converted into mass values with the identical calibration equation. After alignment of the mass scales, mass spectra can be reliably compared with respect to deviations in intensities of bio-makers, or be added together without deterioration in the mass resolution, and improved reference spectrum libraries can be created. Furthermore, the invention allows more reliable library searches to be carried out.

Abstract: The invention relates to a method of a mass-spectrometric analysis of known mutation sites in the genome, such as single nucleotide polymorphisms (SNPs), using the method of restricted primer extension. The invention consists of the use of primers with a photocleavable linker. The linker creates a gap in a DNA strand which is almost the same size as a natural DNA building block (nucleoside). The linker forms a bridge over a base pair without inhibiting hybridization or enzymatic extension. However, the linker allows the primers to be cleaved after extension in order to obtain short DNA fragments which can be more easily detected on the mass spectrometer.

Abstract: The invention generates mass scale comparability between mass spectra which are acquired in time-of-flight mass spectrometers, particularly with ionization by matrix-assisted laser desorption. Always slightly distorted mass scales of different mass spectra from the same type of sample can be aligned. The flight times of identical ions always differ slightly from one mass spectrum to the next due to non-reproducible processes in the ionization method. Thus the apparent mass values of ion signals of identical substances in different mass spectra do not match even if the flight times are converted into mass values with the identical calibration equation. After alignment of the mass scales, mass spectra can be reliably compared with respect to deviations in intensities of bio-makers, or be added together without deterioration in the mass resolution, and improved reference spectrum libraries can be created. Furthermore, the invention allows more reliable library searches to be carried out.

Abstract: The invention relates to a method of investigating by mass spectrometry the genetic material deoxyribonucleic acid (DNA) replicated by polymerase chain reaction (PCR), for the identification of known mutations and polymorphisms; it particularly relates to the analysis of single nucleotide polymorphisms (SNPs) by matrix assisted laser desorption and ionization (MALDI). The invention consists of using a set of nucleoside triphosphates for the selective PCR replication of the DNA in which one or more of the nucleoside triphosphates have been made much heavier by attaching a chemical group, but in such a way that the replication is not disturbed by the polymerase. In this way a single nucleotide polymorphism in DNA pieces with a length of about 40 to 50 bases can very easily be made visible by mass spectrometry without any further manipulation.

Abstract: The invention relates to a method of a mass-spectrometric analysis of known mutation sites in the genome, such as single nucleotide polymorphisms (SNPs), using the method of restricted primer extension. The invention consists of the use of primers with a photocleavable linker. The linker creates a gap in a DNA strand which is almost the same size as a natural DNA building block (nucleoside). The linker forms a bridge over a base pair without inhibiting hybridization or enzymatic extension. However, the linker allows the primers to be cleaved after extension in order to obtain short DNA fragments which can be more easily detected on the mass spectrometer.