Comparative validation of a microcapsule-based immunoassay for the detection of proteins and nucleic acids

Abstract

To detect and study diseases, research and clinical laboratories must quantify specific biomarkers in the plasma and urine of patients with precision, sensitivity, and cost-effectiveness. Newly developed techniques, such as particle-based immunoassays, must be validated in these terms against standard methods such as enzyme-linked immunosorbent assays (ELISAs). Here, we compare the performance of assays that use hollow polyelectrolyte microcapsules with assays based on solid plastic beads, and with standard microplate immunoassays. The polyelectrolyte microcapsules detect the disease biomarker beta-2 microglobulin with a fifty-fold increase in sensitivity than polystyrene (PS) beads. For sequence-specific nucleic acid detection, the oligonucleotide-coated microcapsules exhibit a two-fold lower increase in sensitivity over PS beads. The microcapsules also detect the presence of a monoclonal antibody in hybridoma supernatant at a fifty-six-fold increase in sensitivity compared to a microplate assay. Overall, polyelectrolyte microcapsule-based assays are more sensitive for the detection of protein and nucleic acid analytes than PS beads and microplate assays, and they are viable alternatives as a platform for the rapid quantitative detection of analytes at very low concentrations.

Bioimaging Tools Based on Polyelectrolyte Microcapsules Encoded with Fluorescent Semiconductor Nanoparticles: Design and Characterization of the Fluorescent Properties

“…These data confirm the efficiency of the procedure used for dissolving the core and demonstrate a bright fluorescence signal of the fabricated microcapsules, which can be detected using the corresponding filters, Texas Red and PE in the cases of fluorescence microscopy and flow cytometry, respectively. The prepared polyelectrolyte microcapsules containing QDs in its polymer shell possess higher fluorescent properties comparing to polyelectrolyte microcapsules labeled with conventional dyes such as fluorescein isothiocyanate (FITC) or aminofluorescein [14, 37]. Otherwise, the microcapsules encoded with QDs using the layer-by-layer approach have the brightness comparable or even inferior than that for the microbeads encoded with organic dyes using swelling technique.…”

Lifting the Veil: Characteristics, Clinical Significance, and Application of β-2-Microglobulin as Biomarkers and Its Detection with Biosensors

“…Because only a trace amount of β 2 M passes through the kidneys, highly sensitive and selective techniques that can detect β 2 M through a simple urine test are crucial for addressing this unmet diagnostic need. Therefore, a recent microcapsule-based sandwich assay was established to enable a simple and rapid quantitative measurement for β 2 M, while providing high sensitivity and selectivity at very small sample quantities. , The assay consists of microcapsules that are chemically cross-linked and coated with protein A before binding with antibody (Figure a). The principle of human β-2 microglobulin (hβ 2 M) detection using protein A-coated microcapsules in a sandwich-like assay format is based on the changes in fluorescence signal when the hβ 2 M is relatively sandwiched between a binder and a detector molecule (Figure b).…”

Microfluidic fabrication of novel polymeric core‐shell microcapsules for storage of CO2 solvents and organic chelating agents

“…11 As a result, capsules with tailor-made architectures and high encapsulation efficiencies can be produced, which can be used for encapsulation of fuels for inertial confinement fusion, 12 CO 2 solvents, 13,14 nutrients, 2 and pigments. 15 Other investigated applications include detection of proteins, nucleic acids, and metals ions, 16,17 fabrication of compartmentalized model membranes 18 and microtissues, 19 single-cell screening of biodiversity, 20 and programmed release of active agents. 21,22 Microfluidic fabrication of capsules usually involves generation of core-shell template droplets followed by shell solidification.…”