Bead-based microarray immunoassay for lung cancer biomarkers using quantum dots as labels

Quantitative and multiplexed detection for blood typing based on quantum dot–magnetic bead assay

“…[29][30][31][32][33] Researchers previously developed a multiplex immunoassay system for lung cancer biomarkers using this integration. 29 Additionally H7 via multilayer QD labeling and magnetic beads was demonstrated to be feasible for detecting Escherichia coli O157. 30 However, multiplexed detection of blood group antigens using the system has not been reported.…”

“…Magnetic beads are coupled with monoclonal antibodies or oligonucleotides to capture the target to form stable compounds. Previous studies showed that the beads were coupled with antibody to capture the target antigen, 29 and magnetic beads were used as solid supports to isolate the target DNA. 30 However, the capture probes were replaced with C1q protein, which was coated on beads in our design.…”

Rapid Isolation and Multiplexed Detection of Exosome Tumor Markers Via Queued Beads Combined with Quantum Dots in a Microarray

“…After incubation at 37 °C for 2 h, the exosome-capture beads were resuspended in 1 × PBS with 1% BSA and stored at 4 °C until use. QD probes with detection antibodies were prepared based on the coupling of the thiols (-SH) on the antibodies to the maleimide-activated surface of the QDs by the method described previously [29]. QD probes for carcinoembryonic antigen (CEA; excitation: 490 nm, emission: 625 nm), fragments of cytokeratin 19 (Cyfra21-1; excitation: 490 nm, emission: 525 nm), and pro-gastrin-releasing peptide (Pro-GRP; excitation: 490 nm, emission: 585 nm) were functionalized for subsequent analysis.…”

A magnetite suspension-based washing method for immunoassays using Escherichia coli cells with autodisplayed Z-domains

“…Because immunoassays exploit the highly specific interactions between IgGs and target analytes (antigens), the nonspecific binding of other proteins must be avoided through effective washing processes with detergents such as Tween 20 and sodium dodecyl sulfate [12,13]. Immunoassays incorporating E. coli cells with autodisplayed Z-domains have been performed with either of the following washing steps: (1) centrifugation of E. coli cells to a pellet [14], or (2) magnetic separation of E. coli cells via immobilization on large superparamagnetic beads [15][16][17][18][19][20]. As previously reported, the centrifugal separation of E. coli cells during the washing steps of immunoassays results in the loss of as much as 10% of the cells per washing.…”