Review: General Orientation Guidelines

The page below is a sample from the LabCE course Basic Tissue Orientation and Paraffin Embedding Technique. Access the complete course and earn ASCLS P.A.C.E.-approved continuing education credits by subscribing online.

Learn more about Basic Tissue Orientation and Paraffin Embedding Technique (online CE course)
Review: General Orientation Guidelines

  • Specimens with a longer side versus width, such as core biopsies, are ideally arranged in parallel rows perpendicular to what will be the long axis of the slide.
  • Larger specimens should be embedded face up or face down, ensuring they lie flat and are in one plane.
  • Multiple fragments of any specimen should be embedded within the same level and in a manner that shows the most surface area.
  • Lumen openings must be embedded in the cross-section.
  • Stratified layers should be embedded on the edge to show all layers.
  • Place any dense, rigid, or brittle specimens at an angle to aid microtomy.
  • Leave a large perimeter of paraffin, especially around fatty specimens.
  • Special orientation instructions about the block face are best given.
  • If there are questions or concerns about orientation, it is always best to hold the specimen and ask for assistance from the grossing pathologist's assistant (PA) or pathologist to avoid losing crucial diagnostic information due to incorrect orientation.