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Title: Portable Multiplex Pathogen Detector

Tumor marker concentrations in serum provide useful information regarding clinical stage and prognosis of cancer and can thus be used for presymptomatic diagnostic purposes. Currently, detection and identification of soluble analytes in biological fluids is conducted by methods including bioassays, ELISA, PCR, DNA chip or strip tests. While these technologies are generally sensitive and specific, they are time consuming, labor intensive and cannot be multiplexed. Our goal is to develop a simple, point-of-care, portable, liquid array-based immunoassay device capable of simultaneous detection of a variety of cancer markers. Here we describe the development of assays for the detection of Serum Prostate Specific Antigen, and Ovalbumin from a single sample. The multiplexed immunoassays utilize polystyrene microbeads. The beads are imbedded with precise ratios of red and orange fluorescent dyes yielding an array of 100 beads, each with a unique spectral address (Figure 1). Each bead can be coated with capture antibodies specific for a given antigen. After antigen capture, secondary antibodies sandwich the bound antigen and are indirectly labeled by the fluorescent reporter phycoerythrin (PE). Each optically encoded and fluorescently-labeled microbead is then individually interrogated. A red laser excites the dye molecules imbedded inside the bead and classifies the bead tomore » its unique bead set, and a green laser quantifies the assay at the bead surface. This technology has been proven to be comparable to the ELISA in terms of sensitivity and specificity. We also describe the laser-based instrumentation used to acquire fluorescent bead images Following the assay, droplets of bead suspension containing a mixture of bead classes were deposited onto filters held in place by a disposable plexiglass device and the resultant arrays viewed under the fluorescent imaging setup. Using the appropriate filter sets to extract the necessary red, orange and green fluorescence from the bead array, digital images were captured to computer with a Pixel CCD camera which were subsequently analyzed using customized digital image processing software.« less
Authors:
; ; ;
Publication Date:
OSTI Identifier:
15002775
Report Number(s):
UCRL-JC-149638
TRN: US200420%%58
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Conference
Resource Relation:
Conference: Twenty First Southern Biomedical Engineering Conference, Washington, DC (US), 09/28/2002--09/29/2002; Other Information: PBD: 15 Jul 2002
Research Org:
Lawrence Livermore National Lab., CA (US)
Sponsoring Org:
US Department of Energy (US)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; 59 BASIC BIOLOGICAL SCIENCES; 99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; ANTIBODIES; ANTIGENS; CAMERAS; COMPUTERS; DETECTION; DNA; ENZYME IMMUNOASSAY; FLUORESCENCE; IMAGE PROCESSING; IMMUNOASSAY; LASERS; NEOPLASMS; OVALBUMIN; PATHOGENS; POLYSTYRENE; PROSTATE