title: Evaluation of quantum dot immunofluorescence and a digital CMOS imaging system as an alternative to conventional organic fluorescence dyes and laser scanning for quantifying protein microarrays.
abstract: Organic fluorescent dyes are widely used for the visualization of bound antibody in a variety of immunofluorescence assays. However, the detection equipment is often expensive, fragile, and hard to deploy widely. Quantum dots (Qdot) are nanocrystals made of semiconductor materials that emit light at different wavelengths according to the size of the crystal, with increased brightness and stability. Here, we have evaluated a small benchtop "personal" optical imager (ArrayCAM) developed for quantification of protein arrays probed by Qdot-based indirect immunofluorescence. The aim was to determine if the Qdot imager system provides equivalent data to the conventional organic dye-labeled antibody/laser scanner system. To do this, duplicate proteome microarrays of Vaccinia virus, Brucella melitensis and Plasmodium falciparum were probed with identical samples of immune sera, and IgG, IgA, and IgM profiles visualized using biotinylated secondary antibodies followed by a tertiary reagent of streptavidin coupled to either P3 (an organic cyanine dye typically used for microarrays) or Q800 (Qdot). The data show excellent correlation for all samples tested (R > 0.8) with no significant change of antibody reactivity profiles. We conclude that Qdot detection provides data equivalent to that obtained using conventional organic dye detection. The portable imager offers an economical, more robust, and deployable alternative to conventional laser array scanners.
authors: Division of Infectious Diseases, Department of Medicine, University of California Irvine, Irvine, CA, USA.
authors: Aarti
authors: A
authors: Jain
authors: Division of Infectious Diseases, Department of Medicine, University of California Irvine, Irvine, CA, USA.
authors: Omid
authors: O
authors: Taghavian
authors: Department of Biomedical Engineering, University of California Irvine, Irvine, CA, USA.
authors: Derek
authors: D
authors: Vallejo
authors: Division of Infectious Diseases, Department of Medicine, University of California Irvine, Irvine, CA, USA.
authors: Emmanuel
authors: E
authors: Dotsey
authors: Grace Bio-Labs, Inc, Bend, OR, USA.
authors: Dan
authors: D
authors: Schwartz
authors: Grace Bio-Labs, Inc, Bend, OR, USA.
authors: Florian G
authors: FG
authors: Bell
authors: Grace Bio-Labs, Inc, Bend, OR, USA.
authors: Chad
authors: C
authors: Greef
authors: Division of Infectious Diseases, Department of Medicine, University of California Irvine, Irvine, CA, USA.
authors: D Huw
authors: DH
authors: Davies
authors: Grace Bio-Labs, Inc, Bend, OR, USA.
authors: Jennipher
authors: J
authors: Grudzien
authors: Department of Biomedical Engineering, University of California Irvine, Irvine, CA, USA.
authors: Abraham P
authors: AP
authors: Lee
authors: Division of Infectious Diseases, Department of Medicine, University of California Irvine, Irvine, CA, USA.
authors: Philip L
authors: PL
authors: Felgner
authors: Division of Infectious Diseases, Department of Medicine, University of California Irvine, Irvine, CA, USA.
authors: Li
authors: L
authors: Liang
mesh_terms: D000906:Antibodies / Q000097:blood / Q000276:immunology; D017347:Brucella melitensis / Q000276:immunology / Q000502:physiology; D002006:Brucellosis / Q000097:blood / Q000276:immunology / Q000382:microbiology; D003952:Diagnostic Imaging / Q000379:methods*; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry; D054884:Host-Pathogen Interactions / Q000276:immunology; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D016778:Malaria, Falciparum / Q000097:blood / Q000276:immunology / Q000469:parasitology; D018613:Microscopy, Confocal; D010963:Plasmodium falciparum / Q000276:immunology / Q000502:physiology; D040081:Protein Array Analysis / Q000379:methods*; D045663:Quantum Dots; D015203:Reproducibility of Results; D014615:Vaccinia / Q000097:blood / Q000276:immunology / Q000821:virology; D014616:Vaccinia virus / Q000276:immunology / Q000502:physiology
chemical_list: D000906:Antibodies; D005456:Fluorescent Dyes; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M
keywords: Antibody; Diagnostics; Protein microarray; Quantum dots