RESUMO
Micron scale latex beads are well established as highly biocompatible reagents. Imbibing two fluorescent dyes into the interior of the beads enables the creation of a family of combinatorially colored labels. Previous use of such beads, in flow cytometry for example, has focused on beads of approximately 5 microm diameter. We show here that 280 nm combinatorially labeled particles can be used to create ELISA-style assays in 200 microm scale virtual wells, using digital microscopy as the readout. The utility of this technique is illustrated by profiling the secreted cytokine footprints of peripheral blood mononuclear cells in a multiparametric version of the popular Elispot assay. Doing so reveals noncanonical classes of T lymphocytes. We further show that the secreting cell type can be concurrently identified by surface staining with a cell type specific antibody conjugated to the same multiplexed beads.
Assuntos
Anticorpos/química , Citometria de Fluxo/métodos , Imunoensaio/métodos , Microesferas , Linfócitos T/citologia , Linfócitos T/imunologia , Anticorpos/imunologia , Citocinas/análise , Citocinas/imunologia , HumanosRESUMO
A novel, homogeneous SERS-based cell detection assay was developed for rapid and direct enumeration of circulating tumor cells in the presence of whole blood. Magnetic beads and SERS tags were respectively conjugated to EpCAM and her2 antibodies for the capture and detection of approximately 50 tumor cells/mL in the presence of whole blood in less than 1 h.
Assuntos
Sangue/metabolismo , Células Neoplásicas Circulantes/metabolismo , Análise Espectral Raman/métodos , Antígenos de Neoplasias/química , Apoptose , Moléculas de Adesão Celular/química , Linhagem Celular , Relação Dose-Resposta a Droga , Molécula de Adesão da Célula Epitelial , Humanos , Magnetismo , Microscopia Eletrônica de Transmissão , Modelos Biológicos , Espalhamento de Radiação , Transdução de Sinais , Propriedades de SuperfícieRESUMO
Surface-enhanced Raman scattering (SERS) is an optical detection technique that offers advantages over traditional assay detection technologies, such as fluorescence and chemiluminescence. These advantages include sensitivity, high levels of multiplexing, robustness and ability to perform detection in blood and other biological matrices. Here, we report on the growing field of SERS-active nanoparticles as a novel method for detection, with special emphasis on their use in the field of oncology. We discuss examples of SERS-active nanoparticles used in an assay for PSA, BRCA1 and Her-2, along with examples of nucleic-acid detection. We present data on a novel homogeneous, single-tube, rapid assay for nucleic acid detection and show how it will benefit the oncology community.
