Despite the introduction of enzyme-based immunohistology in the late 1960s and early 1970s by Nakane and Taylor, both methodologic and interpretative aspects of this important technology remain, in large part, manual and not automated. Similar approaches to the analysis and sorting of cell markers by immunofluorescence have been automated for a decade using flow cytometry. Automation of both procedural and interpretative aspects of immunohistology has been the focus of greater commercial and professional attention in recent years. Automated immunostaining is accorded several advantages, including cost savings, uniformity of slide preparation, and reduction of procedural human errors. Automated interpretation may not be necessary or desirable for all types of preparations, but it is logical for quantitation of estrogen and progesterone receptors, infiltrating immunoregulatory populations in tumors, and many other applications.
