An easy method for manual construction of high-density tissue arrays

Tissue array technique is a powerful tool for high-throughput in situ analysis on a large cohort of cases. This report describes an easy and effective method for manual construction of high-density tissue array containing 88 (11 x 8) samples, each of which measures 2 mm in diameter. No extraneous device is needed except a conventional 16-gauge bone marrow biopsy trephine apparatus to puncture the paraffin blocks. The authors constructed 563 cases of epithelial neoplasm into 7 blocks. The sectioning is smooth and does not require adhesive tape. They performed immunohistochemical staining for cytokeratins 7 and 20 on these tissue array slides. The samples rarely fell off during the antigen retrieval and staining procedure. The results were generally in agreement with those in previous reports. The authors offer a satisfactory alternative method for building custom arrays for any laboratory that is unable to afford a tissue array apparatus.