Agilent Technologies

About: Agilent Technologies is a company organization based out in Santa Clara, California, United States. It is known for research contribution in the topics: Signal & Mass spectrometry. The organization has 7398 authors who have published 11518 publications receiving 262410 citations. The organization is also known as: Agilent Technologies, Inc..

High-Throughput SISCAPA Quantitation of Peptides from Human Plasma Digests by Ultrafast, Liquid Chromatography-Free Mass Spectrometry

Abstract: We investigated the utility of an SPE-MS/MS platform in combination with a modified SISCAPA workflow for chromatography-free MRM analysis of proteotypic peptides in digested human plasma. This combination of SISCAPA and SPE-MS/MS technology allows sensitive, MRM-based quantification of peptides from plasma digests with a sample cycle time of ∼7 s, a 300-fold improvement over typical MRM analyses with analysis times of 30-40 min that use liquid chromatography upstream of MS. The optimized system includes capture and enrichment to near purity of target proteotypic peptides using rigorously selected, high affinity, antipeptide monoclonal antibodies and reduction of background peptides using a novel treatment of magnetic bead immunoadsorbents. Using this method, we have successfully quantitated LPS-binding protein and mesothelin (concentrations of ∼5000 ng/mL and ∼10 ng/mL, respectively) in human plasma. The method eliminates the need for upstream liquid-chromatography and can be multiplexed, thus facilitating quantitative analysis of proteins, including biomarkers, in large sample sets. The method is ideal for high-throughput biomarker validation after affinity enrichment and has the potential for applications in clinical laboratories.

Detection of Human Urinary 5-Hydroxymethylcytosine by Stable Isotope Dilution HPLC-MS/MS Analysis

Abstract: The sixth DNA base 5-hydroxymethylcytosine (5hmC) is the major oxidation product of the epigenetic modification 5-methylcytosine (5mC), mediating DNA demethylation in mammals. Reduced 5hmC levels are found to be linked with various tumors and neurological diseases; therefore, 5hmC is an emerging biomarker for disease diagnosis, treatment, and prognosis. Due to its advantages of being sterile, easily accessible in large volumes, and noninvasive to patients, urine is a favored diagnostic biofluid for 5hmC analysis. Here we developed an accurate, sensitive, and specific assay for quantification of 5mC, 5hmC, and other DNA demethylation intermediates in human urine. The urinary samples were desalted and enriched using off-line solid-phase extraction, followed by stable isotope dilution HPLC-MS/MS analysis for 5hmC and 5mC. By the use of ammonium bicarbonate (NH4HCO3) as an additive to the mobile phase, we improved the online-coupled MS/MS detection of 5mC, 5hmC, and 5-formylcytosine (5fC) by 1.8–14.3 times. T...

α-Arrestins Aly1 and Aly2 Regulate Intracellular Trafficking in Response to Nutrient Signaling

Abstract: Arrestins, known regulators of endocytosis, take on novel functions in nutrient-regulated endosomal recycling. Yeast α-arrestins, Aly1 and Aly2, redistribute the Gap1 permease from endosomes to the...

Development of a Liquid Chromatography-High Resolution Mass Spectrometry Metabolomics Method with High Specificity for Metabolite Identification Using All Ion Fragmentation Acquisition.

Abstract: High-resolution mass spectrometry (HRMS)-based metabolomics approaches have made significant advances. However, metabolite identification is still a major challenge with significant bottleneck in translating metabolomics data into biological context. In the current study, a liquid chromatography (LC)–HRMS metabolomics method was developed using an all ion fragmentation (AIF) acquisition approach. To increase the specificity in metabolite annotation, four criteria were considered: (i) accurate mass (AM), (ii) retention time (RT), (iii) MS/MS spectrum, and (iv) product/precursor ion intensity ratios. We constructed an in-house mass spectral library of 408 metabolites containing AMRT and MS/MS spectra information at four collision energies. The percent relative standard deviations between ion ratios of a metabolite in an analytical standard vs sample matrix were used as an additional metric for establishing metabolite identity. A data processing method for targeted metabolite screening was then created, merg...

One chip USB optical mouse sensor solution

Abstract: An apparatus for controlling the position of a screen pointer for an electronic device having a display screen includes a light source for illuminating an imaging surface, thereby generating reflected images. The apparatus includes a single chip for receiving the reflected images, generating digital representations of the reflected images, and generating a first set of movement data based on the digital representations of the reflected images. The first set of movement data is indicative of relative motion between the chip and the imaging surface. The single chip includes a serial interface for outputting motion data in a serial format based on the movement data.