The Advantages of Microarrays and How They Are Used

A tissue microarray is a fairly recent high-throughput application that allows researchers to test hundreds of tissue samples with antibodies of their choice at once.  Essentially, a tissue microarray is a paraffin block that is produced by a composition of tissue cores from paraffin donor blocks within defined coordinates to account for a variety of tissue types. Due to the success of the traditional immunohistochemistry (IHC) experimental method in advancing clinical research and drug discovery, the introduction of high-throughput IHC is pivotal to understanding the transformation of tissues from healthy to malignant. This article will go deeper into the pros and cons of tissue microarrays, as well as introduce tissue array sets available from Bio-Techne and real world applications. 

When it comes to a tissue microarray, the advantages far outweigh any limitations.  To begin, tissue microarrays are an excellent choice when you need to conserve primary antibody usage.  Instead of testing 100 tissue samples via IHC the conventional way, you can now use a minimal amount of your primary antibody to cover more ground.  This is especially helpful when you have a polyclonal antibody that hasn’t been specifically reliable lot to lot or a rare antigen that you don’t have a high volume of.  In addition, being able to screen hundreds of tissues from a similar sample demographic that are all exposed to the same experimental conditions will strengthen produced results.  Furthermore, the opportunity to perform rigorous statistical analysis on a larger sample size will also increase the statistical significance of your conclusions for a fraction of the time and cost typically associated with an IHC experiment.  Limitations with tissue microarray may arise when large populations of tissue sample required are not available, or the cost to purchase the tissue is too high. Furthermore, while a high number of tissue varieties can be tested at once, there are limitations with the number of molecular targets that can be analyzed.  

Rizzo et al used a TRF2 antibody and SIRT6 antibody for a tissue microarray experiment in conjunction with their research on the interaction between SIRT6 and TRF2 in response to DNA damage. In this case, this particular research group created their own tissue microarray from colorectal cancer cores from 185 patients who underwent surgical treatment.  Prior to tissue microarray construction, these samples were histopathologically re-evaluated.  The tissue microarray was stained for a monoclonal TRF2 antibody and a polyclonal SIRT6 antibody.  Their results showed a strong PARP dependent interaction between TRF2 and SIRT6 that increased in the presence of DNA damage.  With this information, Rizzo predicted that high levels of TRF2 in cancer might be a result of decreased levels of SIRT6.  Here their tissue microarray was used to determine that 63 samples stained negative for TRF while 122 scored high, or positive for TRF2.  What’s more, of the 63 negative samples, 49 were high in SIRT6 while 14 were low.  Likewise, in the group of 122 that tested positive for TRF2, 37 samples were SIRT6 high whereas 85 were low.  This finding led this group to discover the inverse correlation between SIRT6 and TRF2. 

Learn more about the properties and varieties of our tissue microarray products.