A micrograph of mouse colon stained with an antibody against a synthetic peptide produced from the sequence of a portion of muc-3. Muc-3 is an intestinal mucin that is largely associated with the brush border of absorptive cells. The image shows the association of muc-3 with the brush border and an accumulation of the released peptide in the luminal mucus gel. The gel serves to protect the mucosal surface of the intestine. This image was collected from a 10 mm frozen section of mouse colon on a BioRad MRC1024 scanning laser confocal microscope.