Minute tissue cylinders (typically 0.6 - 1.0 mm in diameter) are taken from different paraffin/OCT embedded tumor blocks ('donor' blocks) and subsequently assembled in an array-like format into one empty 'recipient' paraffin/OCT Tissue Micro Array (TMA) block. Regular microtomes can be used to cut sections from these TMA blocks. Paraffin- embedded tissues are generally used for TMA construction, because of the availability and the ease of handling paraffin-embedded blocks.