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Pre-analytical stages

It is important that high-quality tumour samples are obtained for PD-L1 testing1. Consideration should be given to each of the following:1,2

  • Sample type, age and location
  • Tissue sample preparation and processing
  • Pathologist QC
Sample type, age and location

Sample type

Routinely processed, FFPE tumour biopsy samples with an adequate number of viable cells are appropriate for use with PD-L1 testing assays2,3

Fine needle aspirate samples have not been validated3

Sample age

Newly acquired and archival tumour biopsies can be used as long as they adhere to standard sample preparation and processing procedures4,5

Sample location

Samples obtained from either primary or metastatic lesions can be used for PD-L1 testing5,6


Professor Keith Kerr discusses the use of cytology samples
for PD-L1 testing

Basic overview of tissue sample preparation and processing*1


*The preparation instructions differ for each PD-L1 assay. For further details, refer to specific package insert for individual assays3,8–10

Embedded sections are cut


Sections are placed onto a slide


Slides are dried...


...and labelled


Slides are loaded in an automated IHC stainer


Quality of staining is checked


Pathologist QC (basic overview)



  1. Cree IA, et al. Histopathology 2016;69:177–186.
  2. Rebellato MC, et al. Diagn Pathol 2016;11:95.
  3. Dako PD-L1 IHC 22C3 pharmDx package insert. http://www.agilent.com/cs/library/packageinsert/public/P03951%20rev%2004.pdf (accessed July 2018).
  4. Herbst RS, et al. Lancet 2016;387:1540–1550.
  5. Midha A, et al. Poster presentation at ASCO 2016 (Abstract 3025).
  6. Zajac M, et al. Poster presentation at AACR 2017 (Abstract 656).
  7. VENTANA PD-L1 (SP263) Assay Staining of NSCLC Interpretation Guide. http://www.roche-diagnostics.ch/content/dam/corporate/roche-dia_ch/ documents/broschueren/tissue_diagnostics/Parameter/lung-pathology/PDF_VENTANA%20PD-L1%20SP263%20Staining%20of%20NSCLC%20Interpretation%20Guide.pdf (accessed July 2018).
  8. VENTANA PD-L1 (SP263) Assay package insert. https://www.accessdata.fda.gov/cdrh_docs/pdf16/P160046C.pdf (accessed July 2018).
  9. Dako PD-L1 IHC 28-8 pharmDx package insert. http://www.accessdata.fda.gov/cdrh_docs/pdf15/P150025c.pdf (accessed July 2018).
  10. VENTANA PD-L1 (SP142) Assay package insert. http://www.accessdata.fda.gov/cdrh_docs/pdf16/P160002c.pdf (accessed July 2018).