Abstract

Background: The isolation of good quality DNA from routinely fixed and processed biopsy samples is crucial for the success of subsequent molecular analysis.

Aims: To compare the amount of β actin DNA extracted from upper gastrointestinal tract biopsies fixed in buffered and unbuffered formalin.

Methods: Amounts of β actin DNA extracted from forceps biopsies of the upper gastrointestinal tract fixed in unbuffered (n  =  22) and buffered formalin (n  =  16) were estimated by quantitative real-time polymerase chain reaction.

Results: The yield of β actin DNA was significantly higher in biopsies fixed in buffered formalin than in those fixed in unbuffered formalin (median 2.8 × 10⁴ and 5.3 × 10² DNA molecules, respectively; p < 0.005). Furthermore, fixation in buffered formalin led to a more reproducible DNA extraction, as indicated by the coefficient of variation (1.0 and 2.2, respectively).

Conclusions: This study indicates that tissue samples should be fixed in buffered formalin to facilitate the use of molecular pathology analysis in routine biopsy material.