The microarray industry is rapidly evolving with companies making substantial investments on research and development to develop new technologies and identify new therapies and diagnostic tests. Certified service providers are offering microarray-based services including genome studies such as genome expression, single nucleotide polymorphism (SNP), copy-number variation (CNV), epigenetic mapping, and diagnostic services. Market players in microarray technology are working closely with a broad network of service providers utilizing their technology platforms, products, instruments, or software for successful execution of services. The recent acquisition of Affymetrix by Thermo Fisher for USD 1.3 billion
demonstrates the industry's belief in the technology.

In May 2016, Avant Diagnostics acquired Amarantus Diagnostics and protein analysis services provider Theranostics Health. The company acquired the appropriate CLIA/CAP infrastructure which has the ability to perform microarray, Western blot, flow cytometry, ELISA, and next-gen sequencing assays.

Also in the month of May 2016, Scienion and Axela entered into a joint array development agreement. Under the terms of the agreement, the companies will jointly develop production systems and services for diagnostic and research products serving oncology, autoimmune, allergy, immunoassay, infectious diseases, and other markets. This will provide commercialization partners with an integrated and scalable offering to address emerging diagnostic markets.

In April 2016, Agilent Technologies partnered with Monash University, Malaysia, to open a jointly run laboratory for proteomics, metabolomics, and multi-omics research. Under the terms of the agreement, Agilent will provide early access to new microarray technology and will collaborate with the school to design arrays for its screening and research projects.

In early 2015, Illumina and collaborators from several consortia developed a new genotyping microarray optimized for genome-wide association studies in populations of diverse ancestries and backgrounds.

Several life sciences areas are trending, in a helpful way, for the microarrays market. Despite the entrance of next-gen sequencing products and predictions of the demise of microarray products, a multi-billion dollar market will remain for the foreseeable future.

Toward Microarray POC Devices

Integration of various steps of the microarray assay into a harmonized and miniaturized handheld device suitable for point-of-care (POC) has been a goal for the microarray community. POC devices are expected to play a growing role in predictive and personalized medicine in the future. On the roadmap to become a POC device, microarray technology needs to overcome several challenges. The first, and probably the most significant challenge, is the integration of the whole assay into a single device. Current microarray technologies use separate instruments for sample preparation, DNA hybridization, signal visualization, and data interpretation. Moreover, some of these components such as the fluorescent scanners used for signal visualization are bulky instruments that are available only in well-equipped laboratories. Another challenge comes from the long reaction time needed in DNA hybridizations, which require 
12-17 hours.

Fortunately, developments in some relevant technologies accelerate this process. For instance, some of the preparation steps for sample labeling can be avoided by using label-free detection approaches. Miniaturization of the spots also alleviates the need for bulky fluorescent scanners. More importantly, with the aid of a microfluidic channel network, all steps of the microarray test can be integrated in a single miniaturized device. In this respect, significant progresses have been achieved in coupling the DNA microarrays with efficient liquid-manipulation microsystems as well as developing novel technologies of supporting subsystems that well suit future POC microarray devices.

Challenges and Opportunities

Since its introduction, the DNA microarray platform has experienced a tremendous growth and currently it is a powerful tool used in various biological applications. It has not been embraced in the molecular diagnostic market as much as it was anticipated in the early days. The challenge comes from the skepticism on the reproducibility of microarray data and on the reliability of the biological interpretations inferred. In addition, the microarray technology is suffering from strong competition from other bio-diagnostic techniques.

While the fierce competition from next-gen sequencing (NGS) at the high end of throughput and from PCR-based techniques at the low end has hindered the DNA microarrays in the molecular diagnostic market, microarrays still have advantages over these competing techniques. The price of NGS assays, although not prohibitive anymore, is still higher than the ones offered by microarray competitors. Some other unresolved difficulties in the sequencing techniques, like the necessity of multiplexing in RNA sequencing as well as of extensive sample preparation and data interpretation, will be in favor of microarrays in the competition.

As the microarray techniques become more familiar for clinicians and more flexible in the sample matrix they can process, they are moving to a better situation in competition with PCR-based techniques. Because of the wealth of knowledge offered by the human genome, the size of the molecular diagnostic market has been largely expanding in the past decade and is assumed to double in 2017. In the presence of NGS, DNA microarrays have continued to exist in the fast-growing molecular diagnostic market, and more microarray-based diagnostic tests are currently gaining regulatory approval and entering the market.

Future Trends

Technical issues observed in the early microarray platforms are mostly resolved in the current platforms. New discoveries about the human genome, thereby increasing the depth of knowledge, would initiate new clinical utilities for DNA microarrays. As microarray technology approaches maturity, many of the issues of the early microarrays have already been overcome and consequently the microarrays are adequately robust and reliable.

Some powerful lab-on-a-chip (LOC) devices have been developed in recent years that have integrated several steps of the assay on their miniaturized platform; however, they are not yet capable of performing an assay without requiring any outside instrument. Particularly, they still need to use the conventional methods for signal detection. Developing novel and compatible supporting technologies that allow their miniaturization is the key factor in developing LOC devices for POC.

Other than fluorescence detection, the label-free detection techniques provide that more simple and powerful technologies will be invented in the future, which will also simplify LOC devices. Different steps of microarray assays are integrated in standalone LOC devices in a more harmonized way, which make them capable of performing sample-in-answer-out assays. These LOC devices exploit the microfluidic networks not only to connect their different compartments but also to help the device become faster to use, smaller, and conveniently controlled. Such LOC devices are suitable candidates for POC diagnostics and play a major role in personalized medicine in the future.

10 Diagnostic Imaging Trends for 2018



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