UCT's Refine™ Ultra-Filtration technology allows for sample precipitation and filtration to occur simultaneously in the individual column/well. A novel, hydrophobically treated, submicron frit combination facilitates the removal of sample proteins without a complicated extraction.
Sample Extraction
a) Place a collection plate under the Refine™ Ultra-Filtration Plate.
b) Add 250 µL of urine and 250 µL Abalonase Ultra Enzyme working solution.
c) Hydrolyze for 30 min at 55 °C.
d) Further dilute sample by adding 500 µL D.I. H2O.
e) Mix sample. This can be executed via vortexing at maximum speed or multiple pipette aspirations and dispenses.
f) Filter the sample using one of the following techniques:
1. Centrifuge: For 5 min at 500 g or until filtrate is collected.
2. Vacuum: Apply vacuum at ~20" of Hg for up to 5 min or until filtrate is collected.
3. Positive Pressure: Apply 2–5 psi using positive pressure for up to 5 min or until filtrate is collected.
LC–MS/MS: Agilent™ 1200 HPLC and AB Sciex™ 4000 Q Trap (MS/MS)
Column: UCT Selectra® DA HPLC column 100 × 2.1 mm, 3 µm
Guard Column: UCT Selectra® DA guard column 10 × 2.1 mm, 3 µm
Injection volume: 10 µL
Mobile phase A: D.I. H2O + 0.1% formic acid
Mobile phase B: MeOH + 0.1% formic acid
Column flow rate: 0.30 mL/min
Table I: Percent reduction in analyte suppression following use of Refine™ plate compared to dilute and shoot preparation for hydrolyzed urine samples.
Using the above procedure, the Refine™ Ultra-Filtration technology allowed for a reduction in instrumental back pressure and removal of unwanted matrix components in urine samples. Overall, this allows for an end user to have enhanced analyte selectivity and an increase in HPLC/UPLC column life.
Figure 1: Back pressure per sample injection of Refine™ Ultra Filtration technology versus a dilute and shoot preparation for hydrolyzed urine samples.
UCT, LLC
2731 Bartram Rd, Bristol, PA 19007
tel: (800) 385-3153
Website:www.unitedchem.com
Top-down characterization of engineered Bcl-xL proteoforms
October 11th 2024Top-down fragmentation enables rapid characterization of phosphorylated proteins without extensive sample preparation and digestion. In this study, electron capture dissociation (ECD) was used to fragment proteoforms of the cell death-related protein, Bcl-xL. Using these methods, 85–90% sequence coverage was achieved for Bcl-xL proteoforms, allowing for effective localization of phosphorylation within minutes.
Antibody peptide mapping using the new Agilent ExD cell
October 11th 2024Enhanced antibody analysis using electron capture dissociation (ECD) allows for precise glycan localization in low-abundance glycopeptides. This study compares the fragmentation of trastuzumab tryptic digests using ECD and collision-induced dissociation (CID). While CID generates abundant glycan HexNAc ions at 204 m/z, ECD preserves the labile glycan group, enabling accurate site localization.
Identification of Amino Acid Isomers Using Electron Capture Dissociation
October 11th 2024Electron capture dissociation produces distinct fragments of amino acid side chains, enabling the identification of isomeric amino acids such as leucine and isoleucine. This application note demonstrates the isomer identification workflow for peptides and intact proteins using the new Agilent ExD cell and ExDViewer software for fragment analysis.
Trends, Best Practices, and Analytical Challenges in Chemical Characterization of Medical Devices
October 7th 2024Chemical characterization of medical devices, including drug-device combination products, is crucial for ensuring regulatory compliance and patient safety by identifying and quantifying chemicals that may interact with the human body. This paper explores current trends, best practices, and regulatory developments in extractables and leachables (E&L) testing for medical devices.