Optical technologies for the read out and quality control of DNA and protein microarrays

Abstract

Microarray formats have become an important tool for parallel (or multiplexed) monitoring of biomolecular interactions. Surface-immobilized probes like oligonucleotides, cDNA, proteins, or antibodies can be used for the screening of their complementary targets, covering different applications like gene or protein expression profiling, analysis of point mutations, or immunodiagnostics. Numerous reviews have appeared on this topic in recent years, documenting the intriguing progress of these miniaturized assay formats. Most of them highlight all aspects of microarray preparation, surface chemistry, and patterning, and try to give a systematic survey of the different kinds of applications of this new technique. This review places the emphasis on optical technologies for microarray analysis. As the fluorescent read out of microarrays is dominating the field, this topic will be the focus of the review. Basic principles of labeling and signal amplification techniques will be introduced. Recent developments in total internal reflection fluorescence, resonance energy transfer assays, and time-resolved imaging are addressed, as well as non-fluorescent imaging methods. Finally, some label-free detection modes are discussed, such as surface plasmon microscopy or ellipsometry, since these are particularly interesting for microarray development and quality control purposes.

Photoluminescence Detection of Biomolecules by Antibody‐Functionalized Diatom Biosilica

“…[1] The immunocomplex is typically detected and quantified by optical, electrical, or mass measurement methods using surfaceimmobilized biomolecules. [2][3][4] Electrical and mass measurement methods are often destructive, invasive, and yield low signal intensities. Furthermore, the labels used in many optical methods can introduce contamination to the sample matrix.…”

Enhanced detection of single-cell-secreted proteins using a fluorescent immunoassay on the protein-G-terminated glass substrate

“…15 Subsequently, fast, high-throughput analysis was readily developed in protein assays since they are based on DNA microarrays. 16,17 The performance of microarray functionalized slides (eg, in terms of signal intensity, signal-to-noise ratio, and spot homogeneity) is dependent on various factors, one of which is the surface moiety for the efficient immobilization of either protein or antibody samples. To improve the detection sensitivity of microarrays, current microarray slides are conferred with a diverse set of surface functionalities by coating them with various units, including, but not limited to, functional groups such as aldehyde, epoxy, and amino groups, and nucleic acids such as DNA.…”

Principles and Application of Microarray Technology in Thyroid Cancer Research

“…The next step is labelling of the molecules with fluorescent dyes; for that step various methods exist. Often the labelling step is done during the enzymatic amplification reaction at which fluorescently labelled nucleotides or primers are incorporated into the newly synthesized amplicons (Schaferling and Nagl, 2006). Nowadays a broad range of fluorescent dyes with different absorption and excitation wavelengths are available.…”