Agar pre-embedding of small skin biopsies: real-life benefits and challenges in high throughput pathology laboratories

J Clin Pathol. 2019 Jun;72(6):448-451. doi: 10.1136/jclinpath-2018-205680. Epub 2019 Feb 20.

Abstract

Paraffin embedding of small, thin tissue samples requires specific expertise for optimal orientation before tissue sectioning. This study evaluates the real-life utility of the agar pre-embedding technique for small skin biopsies with regards to lengthening of work times, problems in orientation (re-embedding) and ancillary techniques (immunohistochemistry and in situ hybridisation) between two high work flow pathology laboratories, one of which routinely uses the agar pre-embedding technique and one which does not. The mean time required for pre-embedding in agar was 30.4 s, but time for paraffin embedding for agar pre-embedded samples was shorter than the traditional method (177 vs 296 s; p<0.005). The number of skin samples requiring re-embedding was significantly higher with the traditional embedding method (p<0.005). No problems in immunoreactivity were observed in all 1900 reactions performed with 17 different antibodies. Fluorescence in situ hybridisation analysis was optimised with a prolonged protease K incubation time (21 vs 18 min).

Keywords: dermatopathology; histopathology; immunohistochemistry; in situ hybridisation; laboratory management.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Agar / chemistry*
  • Biomarkers, Tumor* / analysis
  • Biomarkers, Tumor* / genetics
  • Biopsy
  • High-Throughput Screening Assays*
  • Humans
  • Immunohistochemistry*
  • In Situ Hybridization, Fluorescence*
  • Paraffin Embedding*
  • Pathology, Clinical / methods*
  • Predictive Value of Tests
  • Reproducibility of Results
  • Skin / chemistry*
  • Skin / pathology
  • Skin Neoplasms / chemistry*
  • Skin Neoplasms / genetics*
  • Skin Neoplasms / pathology
  • Time Factors
  • Workflow

Substances

  • Biomarkers, Tumor
  • Agar