A bedpan proved practical for growing penicillin mould at Oxford. Its broad, shallow shape provided a much larger surface area than ordinary laboratory bottles, allowing more mould culture to grow while making better use of limited incubator space.
The Oxford researchers initially used glass bottles laid on their sides, but these were inefficient because most laboratory containers did not offer enough flat growing area. Heatley and his colleagues found that bedpans worked well for surface culture, and the idea led to purpose-built ceramic containers made in Burslem by J. Macintyre and Company.
This was not merely a colourful wartime anecdote: production required many culture vessels, and the team had to improvise with readily available equipment. The vessels were rectangular and stackable, increasing capacity. The mould was grown on the surface of nutrient liquid, rather than inside a modern industrial fermenter. The bedpan therefore solved a practical scaling problem during the early development of penicillin.