Formalin-Fixed Paraffin-Embedded (FFPE) Tissue Blocks
Biosample Hub frequently receives requests for solid tissue, either as paraffin blocks or frozen tissue. Please see our FAQs for Requesters.
In general, paraffin blocks are formalin-fixed paraffin-embedded (FFPE) tissue blocks.
Method for Paraffin-Embedding Tissue Blocks
The following standard operating procedure for paraffin-embedding tissue blocks is provided by the Biobank Resource Centre:
Standard Operating Procedure from CTRNet
Video Showing Formalin-Fixation and Paraffin-Embedding of Tissue Blocks
This video is from the University of Bristol. In summary, it explains formalin fixation and paraffin embedding of tissue blocks in the first 5 minutes. Subsequently, it describes tissue sectioning and staining.
Notes On Solid Tissue Procurement
- A practicing pathologist should supervise tissue procurement to safeguard material needed for diagnosis.
- It is important to realise that solid tissues may be very heterogeneous in composition. For example, tumour samples may be composed of varying proportions of neoplastic cells, normal cells, necrosis and fibrosis. Therefore, a histological section from each aliquot should be examined by microscopy.
- Multiple pre-analytical factors may affect FFPE specimen quality (Bass et al., 2014).
- If not processed immediately, specimens should be kept on wet ice.
- Cross-contamination, dehydration and dessication must be prevented.
- Consider all human specimens as potential biohazards (section F6.1).
From ISBER Best Practices, 2018.
References on FFPE Tissue
Bass BP, Kelly B Engel, Sarah R Greytak, Helen M Moore. A review of preanalytical factors affecting molecular, protein, and morphological analysis of formalin-fixed, paraffin-embedded (FFPE) tissue: how well do you know your FFPE specimen? Arch Pathol Lab Med. 2014 Nov;138(11):1520-30.
Engel KB, Moore HM. Effects of preanalytical variables on the detection of proteins by immunohistochemistry in formalin-fixed, paraffin-embedded tissue. Arch Pathol Lab Med. 2011 May;135(5):537-43.
Grizzle WE, Katherine C Sexton, Walter C Bell. Quality Assurance in Tissue Resources Supporting Biomedical Research. Cell Preserv Technol. 2008 Jul 30;6(2):113-118.
Sadeghipour A., Babaheidarian P. (2019) Making Formalin-Fixed, Paraffin Embedded Blocks. In: Yong W. (eds) Biobanking. Methods in Molecular Biology, vol 1897. Humana Press, New York, NY. https://doi.org/10.1007/978-1-4939-8935-5_22.
DNA and RNA Extraction from Formalin-Fixed, Paraffin-Embedded Tissue Biospecimens. NCI Biospecimen Evidence-Based Practices (BEBP).