Abstract: The present invention relates to the field of biochemistry, more particularly to proteomics, more particularly to protein sequencing, even more particularly to single molecule peptide sequencing. The invention discloses methods for single molecule protein sequencing and/or amino acid identification using cleavage inducing agents which are not specific for one particular amino acid, cleave polypeptides step by step from the N-terminus onwards and provide information on the identity of the cleaved amino acids based on the kinetics.

Abstract: A coagulation test device for measuring clotting time and clot characteristics of a whole blood sample under different hemostatic conditions. Results of the test are used as an aid in management of patients with coagulopathy of unknown etiology in order to help the physician determine appropriate clinical action to arrest bleeding in a patient.

Abstract: A method for quantitatively determining the amount of acetaminophen in a sample with greater precision, greater sensitivity and fewer interactions and fewer spectral and chemical interferences with other compounds contained in the sample. The method includes acetaminophen being hydrolyzed and the resulting p-aminophenol being reacted with a compound of general formula (III): in the presence of an oxidant to form a compound of general formula (IV): wherein R1 and R2, independently of one another, are selected from H, —CH3, and —OCH3, R3 is —C2H5 and R4 is a C1-4 alkyl moiety with a terminal sulfonate group, with the proviso that at least one of R1 and R2 is —OCH3 and/or R4 additionally has at least one OH substituent, and then the amount of the compound of general formula (IV) in the reaction mixture being photometrically determined.

Abstract: Embodiments herein include a method for detecting a brain condition in a subject. The method can include obtaining a breath sample from the subject and contacting it with a chemical sensor element, where the chemical sensor element includes a plurality of discrete graphene varactors. The method can include sensing and storing capacitance of the discrete graphene varactors to obtain a sample data set and classifying the sample data set into one or more preestablished brain condition classifications. Other embodiments are also included herein.

Abstract: Aspects of the application provide methods of identifying and sequencing proteins, polypeptides, and amino acids, and compositions useful for the same. In some aspects, the application provides methods of obtaining data during a degradation process of a polypeptide, and outputting a sequence representative of the polypeptide. In some aspects, the application provides amino acid recognition molecules having a shielding element that enhances photostability in polypeptide sequencing reactions.

Abstract: Methods of quantitating extra-cellular vesicle surface markers are provided. Aspects of the methods include comparing: a mean fluorescence intensity of a surface marker of interest (surface marker MFI) of a labeled extra-cellular vesicle (EV) sample with a calibration plot obtained from a liposome calibration composition to quantitate the surface marker on extra-cellular vesicles of the EV sample. Also provided are compositions that find use in practicing embodiments of the invention.

Abstract: A method of preparing reagents includes inserting a cartridge into an instrument. The cartridge includes a plurality of reagent enclosures disposed in a cavity of the cartridge and exposing a port to an exterior of the cartridge. Each reagent enclosure includes a reagent container including a reagent and an internal cavity defining a compressible volume, an opening defined through the reagent container to the internal cavity. The method further includes connecting a plurality of fluid ports to the openings of the plurality of reagent enclosures; applying a solution through the fluid ports to at least partially fill the plurality of reagent enclosures; and cycling a pressure of the cavity, whereby for each of the reagent enclosures, during increasing pressure, the solution enters the internal cavity of the reagent container, combines with the reagent, and compresses the compressible volume, and during decreasing pressure, the compressible volume decreases and the reagent is ejected through the opening.

Abstract: Methods, systems and techniques for the accurate measurement breath-borne biomarkers are disclosed. Such methods, systems and techniques may be used for the purposes of detection and/or measurement in breath samples of biomarkers.

Abstract: The present document describes a method for the detection of off-flavor maple syrup made from buddy maple sap or maple sap contaminated with buddy maple sap, or off-flavor maple sap. The method involves the measurement of a spectrophotometric property of a nanoparticle reactive with a buddy maple sample having a size of from about 1 nm to about 250 nm contacting a maple syrup or maple sap sample. A change in the spectrophotometric property is associated with an off-flavor maple syrup or maple sap sample, and no change in the spectrophotometric property is associated with a good flavor maple syrup or maple sap sample.

Abstract: An angiosperm index-1 and an angiosperm index-2 are correlated to an age of a liquid hydrocarbon sample and can be used to distinguish oil age of Late Cretaceous (100-65 million years before present, or 100-65 Ma BP) vs. Paleogene (65-55 Ma BP) vs. Eocene or younger (<55 Ma BP). This method improves over existing methods that cannot distinguish oil age between Late Cretaceous and Miocene (ca. 100-5 Ma BP).

Abstract: Analyte collection and testing systems and methods, and more particularly to disposable oral fluid collection and testing systems and methods. Described herein are methods and apparatuses to achieve significant improvements in the detection of fluorescence signals in the reader.

Abstract: Provided are methods of detecting the presence or amount of a vitamin D metabolite in a sample using mass spectrometry. The methods generally directed to ionizing a vitamin D metabolite in a sample and detecting the amount of the ion to determine the presence or amount of the vitamin D metabolite in the sample. Also provided are methods to detect the presence or amount of two or more vitamin D metabolites in a single assay.

Abstract: A method of determining saturate, aromatic, resin, and asphaltene (SARA) fractions of a hydrocarbon fluid sample, including: i) microfluidic mixing that forms a mixture including the hydrocarbon fluid sample and a solvent fluid that dissolves asphaltenes; ii) performing optical spectroscopy on the hydrocarbon fluid sample-solvent fluid mixture resulting from i); iii) microfluidic mixing that forms a mixture including the hydrocarbon fluid sample and a titrant fluid that precipitates asphaltenes; iv) microfluidically precipitating asphaltenes from the hydrocarbon fluid sample-titrant fluid mixture resulting from iii); v) performing a microfluidic filtering operation that removes precipitated asphaltenes from the mixture resulting from iv) while outputting permeate; vi) performing optical spectroscopy on the permeate resulting from v); vii) determining an asphaltene fraction percentage of the hydrocarbon fluid sample based on the optical spectroscopy performed in ii) and vi); viii) sequentially separating sa

Abstract: A first method for determining an amount of water in a sample includes the step of providing a reagent including: sulfur dioxide or a derivative thereof; a base; an optional hydrogen halide or hydrogen halide donor; a solvent; and a sulfonic acid; and the step of titrating the sample with the reagent. A second method for determining an amount of water in a sample includes the step of providing the aforementioned reagent, combining the sample with the reagent; and adding a source of iodine to the sample and/or the reagent. The reagent may alternatively consist essentially of sulfur dioxide or a derivative thereof; imidazole and/or a derivative thereof; an optional hydrogen halide or hydrogen halide donor; acetonitrile; methane sulfonic acid; and methanol and/or ethanol.

Abstract: A sampling device is provided for concentrating a liquid specimen sample, including a filtration assembly, which includes a tubular container and a plunger. The plunger includes a plunger head and a plunger rod that is shaped so as to define an internal plunger space having a plunger-space proximal opening through a proximal end of the plunger rod. The sampling device is configured such that a filter is removable from the tubular container via the plunger-space proximal opening while the plunger head is within the tubular container. Other embodiments are also described.

Abstract: The invention generally relates to systems and methods for quantifying an analyte extracted from a sample. In certain embodiments, the invention provides methods that involve introducing a solvent into a capillary, introducing the capillary into a vessel including a sample such that a portion of the sample is introduced into the capillary, moving the sample and the solvent within the capillary to induce circulation within the sample and the solvent, thereby causing the analyte to be extracted from the sample and into the solvent, analyzing the analyte that has been extracted from the sample, and quantifying the analyte. In certain embodiments, the quantifying step is performed without knowledge of a volume of the sample and/or solvent.

Abstract: The methods and systems may include LC-MS/MS. For example the method may include obtaining MS/MS data for a predetermined MS/MS transition for THC and/or at least one THC metabolite and CBD and/or at least one CBD metabolite, and determining a ratio of the amount of the CBD and/or at least one CBD metabolite to the amount of the THC and/or at least one THC metabolite for the biological sample. In certain embodiments, the methods and/or systems are used to distinguish CBD from THC use in a subject.

Abstract: Microfluidic methods of altering the spacing of a stream of objects. In an exemplary method, objects of the object stream may be transported in carrier fluid along a microfluidic channel structure having an inflow region, an outflow region, and an expanded region extending from the inflow region to the outflow region. The expanded region may have a greater cross-sectional area for fluid flow than each of the inflow region and the outflow region. Objects of the object stream may be moved from the inflow region to the expanded region such that at least a subset of such objects are moved closer to one another. Objects of the object stream may be passed from the expanded region to the outflow region to increase a distance between such objects.

Abstract: A system and method are provided for harvesting target biological substances. The system includes a substrate and a first and second channel formed in the substrate. The channels longitudinally extending substantially parallel to each other. A series of gaps extend from the first channel to the second channel to create a fluid communication path passing between a series of columns with the columns being longitudinally separated by a predetermined separation distance. The system also includes a first source configured to selectively introduce into the first channel a first biological composition at a first channel flow rate and a second source configured to selectively introduce into the second channel a second biological composition at a second channel flow rate. The sources are configured to create a differential between the first and second channel flow rates to generate physiological shear rates along the second channel that are bounded within a predetermined range.

Abstract: Disclosed is an integrated device for faeces sampling and occult blood detection, which has functions of quantitative collection, dissolution, filtration, detection with immune test strips of the faecal sample, and is convenient to carry and operate, and the device does not leak any liquid during storage, transportation and detection. The device can accurately collect a constant sample with no pollution and leakage, and can quickly determine results of occult blood without the aid of other items. The device can detect faecal occult blood at any time and at any place, can help to overcome the problem of low rate of inspection due to the inconvenience of faeces submission and inspection, further promote the detection of faecal occult blood, and can improve the early diagnosis and screening rate of colorectal cancer of the population.