The quality of the histological sections of gastrointestinal biopsies (GIB) affects the diagnostic possibilities. One aspect is the orientation of GIB, whereby sectioning perpendicular to the mucosal surface can be performed more readily. With the purpose to achieve correct orientation, GIB is occasionally mounted on millipore filter (MF) in an attempt to place the deep cut side onto the MF. The importance of this technique for section quality is evaluated in this study.