Two pairs of entire tissue sections with consistent protein expression throughout all the crypts. Panels A and C are sequential tissue sections from a biopsy taken from a 57 year old male patient with current tubulovillous adenomas and a history of colon cancer. Panels B and D are non-sequential tissue sections from a tissue sample taken from a resection from a male patient who had a carcinoma in the sigmoid. Panels A and B were stained for Pms2, panels C and D were stained for XPF. All crypts in each tissue section had similar levels of protein expression, with high (A, C) or low (B, D) protein expression. Images B and D were tiled, since the entire tissue section could not be captured in one field of view. Images taken at 40×.