Tufts OpenCourseware
PREV : G4-1:Lymph Node, Cortex
Author: Alvar W Gustafson, Ph.D.
Description:Section of ileum showing several villi in longitudinal and oblique planes. The clear fissure running from upper center to lower left represents a split in the tissue introduced by the microtome knife during sectioning. This "knife-mark" artifact may be caused either by a nick in the cutting facet of the knife or by an accumulation of debris just behind the cutting surface--located between the knife facet and the block face during the cutting cycle. Also notice the "fading" artifact of the stain at the tips of the villi at far right of field. (ag00)