Apparatuses for preparing a sample are disclosed herein. The apparatuses include a chamber, a first valve at least partially disposed in the first chamber, a second valve at least partially disposed in the first chamber, and a pump comprising an actuator and nozzle.

The instant invention provides an economical flow-through method for determining amount of target proteins in a sample. An antibody preparation (whether polyclonal or monoclonal, or any equivalent specific binding agent) is used to capture and thus enrich a specific monitor peptide (a specific peptide fragment of a protein to be quantitated in a proteolytic digest of a complex protein sample) and an internal standard peptide (the same chemical structure but including stable isotope labels). Upon elution into a suitable mass spectrometer, the natural (sample derived) and internal standard (isotope labeled) peptides are quantitated, and their measured abundance ratio used to calculate the abundance of the monitor peptide, and its parent protein, in the initial sample.

Provided are synthetic dendrimer calibrants for mass spectrometry. The calibrants are distinguished by their relative ease and rapidity of synthesis, comparatively low cost, long shelf life, high purity, and amenability to batch synthesis as mixtures. The latter characteristic enables parallel preparation of higher molecular weight compounds displaying useful distributions of discrete molecular weights, thereby providing multi-point mass spectrometry calibration standards. Methods of making, tuning and using said calibrants are provided.

Transport scheduling and transport processes for low microbial (LM) bulk products are described. The transport scheduling and processes facilitate low microbial activity in a LM bulk product during the transport of the LM bulk product.

A liquid chromatography method for identifying an analyte of interest utilizing as retention index standards a homologous series of neutrally charged compounds having at least one functional group bearing a positive charge and at least one functional group bearing a negative charge. The method is especially useful for liquid chromatography-mass spectrometry (LC-MS) methods, more especially for LC-MS methods employing electrospray (ESI) or atmospheric pressure chemical ionization (APCI) ionization systems.

Transport scheduling and transport processes for low microbial (LM) bulk products are described. The transport scheduling and processes facilitate low microbial activity in a LM bulk product during the transport of the LM bulk product.

A parallel processing system for processing samples is described. In one embodiment, the parallel processing system includes an instrument interface parallel controller to control a tray motor driving system, a close-loop heater control and direction system, a magnetic particle transfer system, a reagent release system, a reagent pre-mix pumping system and a wash buffer pumping system.

A multi-channel system for classifying particles in a mixture of particles according to one or more characteristics including a common source of electromagnetic radiation for producing a beam of electromagnetic radiation and a beam splitter for producing multiple beams of electromagnetic radiation for directing multiple beams of electromagnetic radiation to each interrogation location associated with each flow channel of the multi-channel system.

A device includes: a first portion configured to be grasped by the hand of the user, and a second portion defining a reservoir containing a control material, wherein the control material contains a target analyte in a known or predetermined concentration. A method of verifying the accuracy of an analyte monitoring device includes receiving control information, receiving a fluid sample, identifying the fluid sample as a control solution, and analyzing the control solution.

Provided are methods of detecting the presence or amount of a dihydroxyvitamin D metabolite in a sample using mass spectrometry. The methods generally comprise ionizing a dihydorxyvitamin 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. In certain preferred embodiments the methods include immunopurifying the dihydroxyvitamin D metabolites prior to mass spectrometry. Also provided are methods to detect the presence or amount of two or more dihydroxyvitamin D metabolites in a single assay.