Preventing Cross-Contamination

Need multiple seats for your university or lab? Get a quote
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)
Preventing Cross-Contamination

Good practices and careful attention can prevent contamination from block to block from occurring during the embedding step.
  1. Open only ONE cassette at a time.
  2. Open lids, mesh bags, and lens papers carefully to avoid specimen fragments from "flipping" outward and potentially being lost.
  3. Wipe forceps between each specimen. Be especially careful with forceps bearing small "teeth" or grooves at the tips. Additionally, the heated wells of embedding center instrumentation that holds forceps should also be cleaned routinely to avoid cross contamination.
  4. Wash non-disposable base molds frequently. It is good practice to wipe a mold that has previously been used with a gauze pad before using for another specimen.
  5. Embed any pieces that appear to "not belong" or to be contamination from grossing or handling into a far corner of the block face away from what you believe to be the intended specimen. This communicates that you think it "doesn't belong" and makes it easy to identify/locate for removal from the block if it is determined that it is a contamination.