Tissue Microarrayers for Immuno-Histopathology
In the ever-evolving field of pathology, tissue microarrayers (TMA) are a recent development that overcomes the time consuming and labour intensive operations involved with traditional histo-pathological sample preparation. These instruments allow you to generate many small representative samples from a single tissue sample quickly and with relative ease.
A TMA extracts cylindrical cores from a donor paraffin block and embeds the cores into a recipient microarray block at predetermined co-ordinates. In doing so, many hundreds of tissue samples can be arrayed into a single paraffin block. These blocks are then sectioned to produce microscope slides for analysis of histopathology, molecular markers at the DNA, mRNA, and protein level.
This enables you to perform high throughput histologic analyses of multiple samples simultaneously. The tissue microarrays also permit simultaneous analysis under identical, standardised conditions from a single glass slide, improving repeatability and consistency.
Analysis using TMA facilitates the identification of new diagnostic and prognostic markers and targets in human cancers, oncology and other tissue-based research areas.
Advantages of Tissue Microarrays
- Produce more samples from a given specimen due to increased accuracy.
- Permits larger number of samples/individual assays => high throughput data acquisition => better statistical analysis
- Improved experimental uniformity with larger numbers of samples on a single slide, processing identically across a larger number of samples, including histochemical stains, immunologic stains with either chromogenic or fluorescent visualisation, in situ hybridisation (including both mRNA-ISH and FISH), and even tissue micro-dissection techniques
- Decreased assay volume, time and cost – Only a small volume of reagent is required to analyse all samples on a given slide reducing costs. This increases efficiency and reduces labour making it very cost effective
- Original block is not destroyed – beneficial when the original block needs to be returned for storage, even after original sample has been cored
- Once created, the TMA can be used in future studies
TMA is Quality Assurance
TMA is an effective and efficient tool for ensuring consistency both within a single lab and between various labs for immuno-histochemical and molecular analyses. By producing a TMA block and sectioning, multiple samples can be produced that can be used to standardise experimental procedures between labs, look for drifts in existing procedures or to optimise diagnostic reagents e.g. monoclonal antibodies or gene probes.
TMA is a practical and efficient methodology for high-throughput molecular analyses of tissues. It is proving to be of value in the identification of new diagnostic and prognostic markers and targets in human cancers. The popularity of the technique is growing in fields such as prognostic oncology and drug discovery where high efficiency sample preparation aids statistically relevant results that then accelerate research, aiding in the translation of molecular discoveries into clinical applications.