Combination of nucleic acid and protein isolation with tissue array construction: using defined histologic regions in single frozen tissue blocks for multiple research purposes.

Precise dissection of defined histological regions for nucleic acid and protein isolation is a precedent step in finding out cancer-related alterations, and high quality tissue microarrays are demanded in the validation of screened genetic alterations by multiple in situ approaches. In this study, a combined technique was developed by which sample isolation and tissue array construction could be performed on the defined morphological region(s) in single tissue block. The RNA and protein samples generated from the selected portions were of good quality and sufficient for multiple experimental purposes. The frozen tissue arrays constructed on a novel recipient are suitable for multiple in situ evaluations including immunohistochemical staining and mRNA hybridisation. In most cases, the data obtained from in situ assays coincided well with the ones revealed by RT-PCR and Western blot hybridisation. The potential experimental bias caused by cell contamination can be amended by tissue array-based retrospective examination. The combination of tissue-selective sample preparations with tissue array construction thus provide a tool by which comprehensive cancer research can be performed on defined histological regions in a series of single frozen tissue blocks.