MULTITISSUE BLOCKS FOR QUALITY-CONTROL IN IMMUNOHISTOCHEMISTRY

A simple method for preparing multitissue control blocks (MTCB) for im munohistochemistry is described. Parallel rectangular tissue sections are embedded in paraffin and sections cut from these blocks are mounte d at one end of the glass slide. A section from the tissue to be stain ed is mounted at the other end of the same glass slide. The slide cont aining both the control and test sections is processed for immunohisto chemistry, allowing both the tissue sample and the controls to be trea ted equally in all steps. The control blocks can be tailored to includ e different tissues or tissues fixed in different fixatives, according to the needs of the laboratory. In contrast to MTCBs that contain lar ge numbers of sections, ours provides adequate tissue for each positiv e control and at the same time allows improved accuracy and diagnostic sensitivity. MTCBs can be used as general control blocks for the majo rity of routine immunohistochemical stains and for initial antibody sc reening.