Implementing reversed-phase and hydrophilic interaction liquid chromatography into the characterization of DTPA-ramucirumab conjugate before radiolabeling.

Radioimmunoconjugates represent a promising class of therapeutics and diagnostics. The characterization of intermediate chelator-antibody products, i.e.

Easy, Robust, and Repeatable Online Acid Cleavage of Proteins in Mobile Phase for Fast Quantitative LC-MS Bottom-Up Protein Analysis─Application for Ricin Detection.

Sample preparation involving the cleavage of proteins into peptides is the first critical step for successful bottom-up proteomics and protein analyses. Time- and labor-intensiveness are among the bottlenecks of the commonly used methods for protein sample preparation. Here, we report a fast online method for postinjection acid cleavage of proteins directly in the mobile phase typically used for LC-MS analyses in proteomics.

Distribution of energy in the ideal gas that lacks equipartition.

The energy and velocity distributions of ideal gas particles were first obtained by Boltzmann and Maxwell in the second half of the nineteenth century. In the case of a finite number of particles, the particle energy distribution was obtained by Boltzmann in 1868. However, it appears that this distribution is not valid for all vessels.

Reversed-Phase Liquid Chromatography of Peptides for Bottom-Up Proteomics: A Tutorial.

The performance of the current bottom-up liquid chromatography hyphenated with mass spectrometry (LC-MS) analyses has undoubtedly been fueled by spectacular progress in mass spectrometry. It is thus not surprising that the MS instrument attracts the most attention during LC-MS method development, whereas optimizing conditions for peptide separation using reversed-phase liquid chromatography (RPLC) remains somewhat in its shadow. Consequently, the wisdom of the fundaments of chromatography is slowly vanishing from some laboratories.

Evaluation of strategies for overcoming trifluoroacetic acid ionization suppression resulted in single-column intact level, middle-up, and bottom-up reversed-phase LC-MS analyses of antibody biopharmaceuticals.

A wide range of strategies for efficient chromatography and high MS sensitivity in reversed-phase LC-MS analysis of antibody biopharmaceuticals and their large derivates has been evaluated. They included replacing trifluoroacetic acid with alternative acidifiers, relevancy of elevated column temperature, use of dedicated stationary phases, and counteraction of the suppression effect of trifluoroacetic acid in electrospray ionization. At the column temperature of 60 °C, which significantly reduces in-column protein degradation, the BioResolve RP mAb Polyphenyl, BioShell IgG C columns performed best using mobile phases with full or partial replacement of trifluoroacetic acid with difluoroacetic acid in the analysis of intact antibodies.