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

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).