Ultra-High-Density Pile-Up Array: A Handy Method for Composing a High-Throughput Tissue Microarray Without Coring Blocks

The aim of this study was to validate the ultra-high-density pile up array (UHPA) method, which enables the composition of a tissue microarray capable of supporting thousands of cases from sectioned tissues, as an alternative and innovative new research method and to evaluate the accuracy and usefulness as a high-throughput method. We used this method to make three tissue microarrays with (1) 2,000 cores (UHPA 2000) using normal kidney tissue to examine the limitations; (2) 400 cases (UHPA 400) to examine the core loss rates and the adaptability of 12 different kinds of cancer; and (3) 84 liver cores (UHPA 84) to validate the adaptability and heterogeneity. The maximum number of 24,000 tissue specimens were arranged onto a single slide glass. The core loss rate was low in all tissue types, ranging from 0%-10.0%, and the adaptation rate ranged from 78.0%-100% in 12 kinds of cancer. UHPA84 using hepatocellular carcinoma and cirrhotic liver tissues showed that more than 90% of cores were identifiable. We developed our novel UHPA method that enables the preparation of Tissue microarrays from sections and increases the output of high-throughput analyses.