Tissue microarray use on the rise

There is a growing reliance on the use of tissue microarrays to accelerate the examination of histological samples used in drug discovery, according to a new report from market research company BioInformatics​.

Large-scale and high-throughput genomic and proteomic studies are generating vast amounts of data that are already leading to the identification of drug targets and disease biomarkers. The new challenge, according to BioInformatics, is to sift through all of this gene and protein expression data to find clinically relevant information.

"A rate-limiting step in the screening process has been the need to examine histological samples one at a time. This degree of scrutiny is necessary to interpret the often complex expression and distribution patterns of target molecules in within actual tissues,"​ notes the report.

To overcome this limitation, tissue microarrays have been developed that allow hundreds of tissue specimens to be examined on a single microscope slide, streamlining the processes of drug discovery and clinical diagnosis.

In contrast to traditional tissue analysis techniques, which use at least one slide for every tissue from each patients or test subject, tissue microarrays are created with specialised instrumentation that can remove small, circular punches from tissue specimens and array up to 1,000 different samples on the same slide.

The microarrays have the benefit of being suitable for scanning using established scanning technologies, and a number of approaches are used to archiving and analysing the resulting visual data. Moreover, the approach uses less tissue resources and reagents, notes the report, which was based on interviews with more than 250 researchers, physicians and technicians who use tissue microarrays.

The respondents reported a broad range of applications for the technology, including studies that attempt to link gene expression data with stages of tumour progression, screening and validation of drug targets and quality control for molecular detection methods.

Among the findings of the survey were that 64 per cent of respondents who do not yet, but plan to use tissue microarrays, believe they will adopt the new technology within the next year. The most common application for the approach was 'basic research on specific genes or proteins,' cited by 64 per cent of those surveyed.

Invitrogen, BD Biosciences, Pharmingen and Ambion were mentioned most often as the primary commercial suppliers of the technology, while more than 30 per cent of respondents said they used their an instrument created in-house to produce tissue microarrays.

There appeared to be significant scope for the development of automated scanning technologies, with 57 per cent of those surveyed saying they used microscopes for this purpose and 53 per cent relying on a manual staining system or instrument.