Tissues were fixed in formalin after excision, and embedded in paraffin. Paraffin tissue arrays are 5-10um in thickness, and mounted on positively charged glass slides. Each tissue sample is about 2mm in diameter. A reference chart shows all the tissue names and their respective position on the array. This product can be used for both immunohistochemistry and in situ hybridization. It is an ideal product for rapid cellular localization of RNA and protein expression.