Specimen Preparation Guide for Clinical Use: FFPE

To ensure submitted specimens yield sufficient amounts of extracted DNA and/or RNA for sequencing and analysis, we have provided the following guidelines below for solid tumors. Unacceptable specimens include hematolymphoid malignancies or decalcified bone.

FFPE — Specimen Preparation

Guidelines for FFPE preparation:

  • Fix tissue samples in 4–10% neutral buffered formalin as quickly as possible after surgical removal.
  • Use a fixation time of 14–24 hours (longer fixation times may lead to more severe DNA fragmentation, resulting in poor performance in downstream assays).
  • Thoroughly dehydrate samples prior to embedding (residual formalin can inhibit the proteinase K digest).
  • FFPE sections should be as fresh as possible. Older FFPE sections may yield poorer results.
  • For core biopsy, use 3–5 cores laid down so that when cut, the blade is running parallel to the long axis of the cores.