Sampling of surfaces can be performed using Thermo Scientific Contact Plates. A sample is taken by gently rolling the domed surface of the agar (the jelly-like medium contained in the plate) onto the area to be tested. If any micro-organisms are present, they will grow to form easily visible colonies on the surface of the agar. This offers a reliable and effective way of determining the microbial cleanliness of surface areas.

An alternative to the contact plate is the Thermo Scientific Dip Slide. This is a plastic slide, coated with an even layer of agar on both sides. This allows two tests to be performed at one time, and increases the detection potential of the method. A flexible hinge between the handle and the slide itself, allows the entire surface of the medium to be gently and evenly pressed onto the area to be tested.

Once samples have been taken, the plates should be covered (Dip Slides returned to their containers) and transported to the laboratory to be incubated appropriately and examined for growth. Each colony represents one micro-organism or colony forming unit (CFU) on the area sampled. The bases of Contact Plates and slides are sub-divided into grids to allow easy calculation of CFU per cm2 from surface tests. The laboratory is then able to report back whether these levels fall within pre- defined acceptable limits.

The measurement of cleanliness in hospitals goes beyond what can be seen by eye. Invisible dangers of microbial contamination can cause the most harm and Trusts will be expecting cleaning contractors to demonstrate extra care and attention in this critical area of hygiene assurance.

For more information contact Carlene Simmons:

Tel: +[44] (0) 1256 841144
Email: leslie.bissell@thermofisher.com
Website: www.oxoid.com