Accelerated colorimetric immunosensingusing surface-modified porous monolithsand gold nanoparticles

A rapid and sensitive immunoassay platform integrating polymerized monoliths and gold nanoparticles (AuNPs) has been developed. The porous monoliths are photopolymerized in situ within a silica capillary and serve as solid support for high-mass transport and high-density capture antibody immobilization to create a shorter diffusion length for antibody–antigen interactions, resulting in a rapid assay and low reagent consumption. AuNPs are modified with detection antibodies and are utilized as signals for colorimetric immunoassays without the need for enzyme, substrate and sophisticated equipment for quantitative measurements. This platform has been verified by performing a human IgG sandwich immunoassay with a detection limit of 0.1 ng ml−1. In addition, a single assay can be completed in 1 h, which is more efficient than traditional immunoassays that require several hours to complete

Trypsin-induced proteome alteration during cell subculture in mammalian cells

<p>Abstract</p> <p>Background</p> <p>It is essential to subculture the cells once cultured cells reach confluence. For this, trypsin is frequently applied to dissociate adhesive cells from the substratum. However, due to the proteolytic activity of trypsin, cell surface proteins are often cleaved, which leads to dysregulation of the cell functions.</p> <p>Methods</p> <p>In this study, a triplicate 2D-DIGE strategy has been performed to monitor trypsin-induced proteome alterations. The differentially expressed spots were identified by MALDI-TOF MS and validated by immunoblotting.</p> <p>Results</p> <p>36 proteins are found to be differentially expressed in cells treated with trypsin, and proteins that are known to regulate cell metabolism, growth regulation, mitochondrial electron transportation and cell adhesion are down-regulated and proteins that regulate cell apoptosis are up-regulated after trypsin treatment. Further study shows that bcl-2 is down-regulated, p53 and p21 are both up-regulated after trypsinization.</p> <p>Conclusions</p> <p>In summary, this is the first report that uses the proteomic approach to thoroughly study trypsin-induced cell physiological changes and provides researchers in carrying out their experimental design.</p