Tissue microarrays are an ideal tool in high-throughput analysis for antigen distribution or validation of newly identified pathogenetic genes. Tissue microarrays with up to 100 individual tissue samples on a single slide minimise variations in staining intensity, yielding consistent results. Tissue spots with a diameter of up to 3 mm provide sufficient area for morphological evaluation. Tissue microarrays provide a rapid solution for localisation of DNA or protein molecules in normal and pathological human tissues.