The present invention refers to a method for isolating a nucleic acid, said method comprising: a) provision of a fluid test sample, which comprises i) a biological sample, ii) a chaotropic agent with a concentration of at least 1 M in the fluid test sample, and iii) a detergent, b) contacting said fluid test sample with a medium for size-exclusion chromatography, and c) purifying the nucleic acid with size- exclusion chromatography. The present invention further relates to the use of any of the methods according to the present invention for detecting a viral infection as well as to a method for detecting a viral infection. The present invention further relates to a kit-of-parts comprising a medium for size- exclusion and a size-exclusion chromatography device for isolating the nucleic acid of the fluid test sample.

A manually actuated chromatography device comprising a chamber for receiving a liquid sample, a pump with a metering valve, and a chromatography element, wherein the pump moves a predetermined volume of liquid from the sample chamber to the chromatography element.

A manually actuated chromatography device comprising a chamber for receiving a liquid sample, a pump with a metering valve, and a chromatography element, wherein the pump moves a predetermined volume of liquid from the sample chamber to the chromatography element.

A fractional concentration of clinically-relevant DNA in a mixture of DNA from a biological sample is determined based on amounts of DNA fragments at multiple sizes. For example, the fractional concentration of fetal DNA in maternal plasma or tumor DNA in a patient's plasma can be determined. The size of DNA fragments in a sample is shown to be correlated with a proportion of fetal DNA and a proportion of tumor DNA, respectively. Calibration data points (e.g., as a calibration function) indicate a correspondence between values of a size parameter and the fractional concentration of the clinically-relevant DNA. For a given sample, a first value of a size parameter can be determined from the sizes of DNA fragments in a sample. A comparison of the first value to the calibration data points can provide the estimate of the fractional concentration of the clinically-relevant DNA.

A fractional concentration of clinically-relevant DNA in a mixture of DNA from a biological sample is determined based on amounts of DNA fragments at multiple sizes. For example, the fractional concentration of fetal DNA in maternal plasma or tumor DNA in a patient's plasma can be determined. The size of DNA fragments in a sample is shown to be correlated with a proportion of fetal DNA and a proportion of tumor DNA, respectively. Calibration data points (e.g., as a calibration function) indicate a correspondence between values of a size parameter and the fractional concentration of the clinically-relevant DNA. For a given sample, a first value of a size parameter can be determined from the sizes of DNA fragments in a sample. A comparison of the first value to the calibration data points can provide the estimate of the fractional concentration of the clinically-relevant DNA.

The present invention relates to the field of RNA analysis. In particular, the invention concerns the use of a catalytic nucleic acid molecule for the analysis of an RNA molecule. The invention concerns methods for analyzing the 5′ terminal structures of an RNA molecule having a cleavage site for a catalytic nucleic acid molecule. In particular, the invention concerns a method for determining the presence of a cap structure in an RNA molecule having a cleavage site for a catalytic nucleic acid molecule, a method for determining the capping degree of a population of RNA molecules having a cleavage site for a catalytic nucleic acid molecule, a method for determining the orientation of the cap structure in a capped RNA molecule having a cleavage site for a catalytic nucleic acid molecule and a method for determining relative amounts of correctly capped RNA molecules and reverse-capped RNA molecules in a population of RNA molecules, wherein the population comprises correctly capped and/or reverse-capped RNA molecules that have a cleavage site for a catalytic nucleic acid molecule. Moreover, the present invention provides uses of a catalytic nucleic acid molecule.

The present invention relates to the field of RNA analysis. In particular, the invention concerns the use of a catalytic nucleic acid molecule for the analysis of an RNA molecule. The invention concerns methods for analyzing the 5′ terminal structures of an RNA molecule having a cleavage site for a catalytic nucleic acid molecule. In particular, the invention concerns a method for determining the presence of a cap structure in an RNA molecule having a cleavage site for a catalytic nucleic acid molecule, a method for determining the capping degree of a population of RNA molecules having a cleavage site for a catalytic nucleic acid molecule, a method for determining the orientation of the cap structure in a capped RNA molecule having a cleavage site for a catalytic nucleic acid molecule and a method for determining relative amounts of correctly capped RNA molecules and reverse-capped RNA molecules in a population of RNA molecules, wherein the population comprises correctly capped and/or reverse-capped RNA molecules that have a cleavage site for a catalytic nucleic acid molecule. Moreover, the present invention provides uses of a catalytic nucleic acid molecule.

The present invention relates to a method for distinguishing a first nucleic acid sequence from a second nucleic acid sequence by electrophoresis. The first nucleic acid comprises a first common sequence tract, a variable sequence tract and a second common sequence tract and the second nucleic acid comprises a first common sequence tract, optionally an variable sequence tract and a second common sequence tract. The first and the second nucleic acid sequence is contacted with a probe sequence that is reverse complementary to the first and second common sequence tract under conditions allowing the hybridization of the probe sequence to the first and second nucleic acid sequence, thereby forming a first probe hybrid and a second probe hybrid. Subsequently, the first and second probe hybrids are submitted to electrophoresis to detect the electrophoretic mobility of the first and second probe hybrid.

The present invention relates to a method for distinguishing a first nucleic acid sequence from a second nucleic acid sequence by electrophoresis. The first nucleic acid comprises a first common sequence tract, a variable sequence tract and a second common sequence tract and the second nucleic acid comprises a first common sequence tract, optionally an variable sequence tract and a second common sequence tract. The first and the second nucleic acid sequence is contacted with a probe sequence that is reverse complementary to the first and second common sequence tract under conditions allowing the hybridization of the probe sequence to the first and second nucleic acid sequence, thereby forming a first probe hybrid and a second probe hybrid. Subsequently, the first and second probe hybrids are submitted to electrophoresis to detect the electrophoretic mobility of the first and second probe hybrid.

Detection and identification of microbial species uses liquid chromatography as a bulk filtration process for rapid isolation and collection of microbial RNA from a biological specimen. In various embodiments, gene sequencing of microbial RNA molecules from a biological specimen is enhanced by obtaining and then preparing the biological specimen as a test sample for liquid chromatography that is used to bulk filter microbial RNA molecules from a mixture of RNA molecules in the test sample to isolate and collect the microbial RNA molecules in two or more fraction outputs, wherein at least one of the two or more fraction outputs is a fraction within a void volume of the liquid chromatography, preparing one or more fraction outputs for gene sequencing, including the fraction output that is within the void volume, and conducting gene sequencing on the one or more prepared outputs to detect microbial RNA from the biological specimen.