The use of Lenticules for the process control of enumeration techniques in food and environmental microbiology

Lenticules consist of control-dried plano convex discs in which biologically-active materials are contained within a water-soluble matrix. They can be produced to contain stable numbers of bacteria from 10 cfu lenticule-1 to 108 cfu lenticule-1 with a wide variety of organisms. These experiments were carried out to validate their use as a tool for internal quality control in quantitative microbiology.

The Lenticules were used routinely in standard quantitative microbiological procedures across five laboratories. Results showed the materials to be stable, homogeneous and capable of identifying systematic errors.

The Lenticules provide suitable, stable control materials.

Routine internal quality control of quantitative measurements is greatly improved; the materials are easy to use and enable comparisons between laboratories to be made.