Most of the immunohistochemical staining that we look at during our diagnostic work is familiar but sometimes we start to use new antibodies or we encounter new proteins in a research environment. When that happens we want to look at some pictures of positive staining with the unfamiliar antibody. Typing the name of the antibody into Google and looking at the images often works but there is a much more effective resource – the Human Protein Atlas. This project, funded by the Knut & Alice Wallenberg Foundation, has used an amazing 24028 antibodies on 213 different human tissues and cell lines so you can usually find what you are looking for! The staining of the tissue array cores can be visualised as virtual slides allowing you to move around and look for subtle features in the staining patterns. Look at the oestrogen receptor images for an introduction to a great website. I have put a permanent link to the Atlas in the Immunohistochemistry section on PathCentral.