Bead-based spontaneous Raman codes for multiplex immunoassay.

In the immunoassay process, for fulfilling the need to identify multiple analytes in a small amount of complex sample matrix, it is desirable to develop highly efficient and specific multiplex suspension array technology. Raman coding strategy offers an attractive solution to code the suspension arrays by simply combing narrow spectral bands with stable signal intensities through solid-phase synthesis on the resin beads. Based on this strategy, we report the bead-based spontaneous Raman codes for multiplex immunoassay. The study resulted in superior selectivity of the Raman-encoded beads for binding with single and multiple analytes, respectively. With the use of mixed types of Raman-encoded immunoassay beads, multiple targets in small amounts of samples were identified rapidly and accurately. By confirming the feasibility of bead-based spontaneous Raman codes for multiplex immunoassay, we anticipate this novel technology to be widely applied in the near future.

Establishment and Preliminary Application Analysis of A Multiplex Detection Method for Influenza A and B Virus Antigen Based on Quantum Dot-encoded Microsphere Flow Cytometry Technology / 现代检验医学杂志

Objective To establish a multiplex assay method for the simultaneous detection of FluA and FluB virus(IBV)antigen based on the flow cytometry(FCM)quantum dot-encoded bead technologies,laying the foundation for the assay of multiple respiratory virus biomarkers.Methods Coupling was performed for FluA and FluB nucleoprotein(NP)monoclonal antibodies using self-made quantum dot-encoded beads,separately.FCM was used to detect known concentrations of FluA and FluB antigens separately and simultaneously,optimize the detection conditions,and establish a joint detection method for FluA and FluB antigens.Compared with the quantitative real-time PCR(qPCR)method,clinical samples were used to evaluate the clinical performance of this joint detection method.Results The joint detection method for FluA and FluB antigens was established,with detection limits of 26.1 pg/ml and 10.7 pg/ml,respectively,and measurement ranges of 15.3～250 000 pg/ml.The joint detection method for clinical sample evaluation was well correlated with the qPCR,with a positive coincidence rate of 57.4%,a negative coincidence rate of 100%,and a total coincidence rate of 71.6%.In addition,the joint detection method was superior to colloidal gold immunochromatographic strip assay commonly used in clinical practice(positive coincidence rate of 56.49%,negative coincidence rate of 99.75%).Conclusion The FCM quantum dot-encoded bead multiplex assay can be used for the joint detection of FluA and FluB antigens,which have a high sensitivity,good specificity and wide detection range.It may lay a good foundation for the multiplex detection of common respiratory viruses,and has clinical application prospects.

Design and Combinatorial Development of Shield-1 Peptide Mimetics Binding to Destabilized FKBP12.

On the basis of computational design, a focused one-bead one-compound library has been prepared on microparticle-encoded PEGA1900 beads consisting of small tripeptides with a triazole-capped N-terminal. The library was screened towards a double point-mutated version of the human FKBP12 protein, known as the destabilizing domain (DD). Inspired by the decoded library hits, unnatural peptide structures were screened in a novel on-bead assay, which was useful for a rapid structure evaluation prior to off-bead resynthesis. Subsequently, a series of 19 compounds were prepared and tested using a competitive fluorescence polarization assay, which led to the discovery of peptide ligands with low micromolar binding affinity towards the DD. The methodology represents a rapid approach for identification of a novel structure scaffold, where the screening and initial structure refinement was accomplished using small quantities of library building blocks.