[Histonet] Tissue microarrays use?

[Madary, Joseph]

Can someone explain to me what the big deal is on tissue microarrays?  I understand that they are many perfect circles of known diseased or normal tissues than can be used as a control for various applications. What are the applications for this stuff on routine or research that would make it worth it for us to either do it ourselves or contract it out?  Can it be done in house cheap?