Cleaning Validation of Medical Devices

Radioactive Labeling (RNM) and direct Protein Detection (OPA, BCA etc.)

The complexity of modern surgical instruments can make their cleaning a considerable challenge. Visual verification of the effectiveness of cleaning may be impossible without disassembly or destruction of the instruments. Furthermore, visual inspection provides only a qualitative evaluation of the cleanliness of the instrument and will miss biologically-important protein residues like blood fibrin that are invisible to the naked eye.

The radionuclide method (RNM) is the method of choice for evaluation and validation of cleaning processes for surgical instruments with areas that cannot be observed directly.

Using radioactive labelling of the test soil provides a reliable, non-destructive analysis of the amount and location of radioactivity remaining after the cleaning process that does not depend upon extraction of residual soil.

An overlay of a standard optical image and a false-color representation of the intensity of radioactivity bound to test soil on and in an instrument pre and post processing (see images to the right) provides visual indication of the location and quantity of residual soil. Analysis of the residual radioactivity provides information on the success of the cleaning process and localization of areas that are difficult to clean.

RNM testing does not interfere with traditional extraction analyses. After the cleaning process and RNM analysis is finished, remaining residual soil is extracted and quantitatively investigated spectrophotometrically for protein content per ISO 15883 and hemoglobin, providing two independent measurements of cleanliness as required by standards and regulatory agencies.

Validations possible using the following washer-desinfectors:

  • Gettinge GEM
  • Gettinge S-8668
  • Steelco DS600 / DS1000
  • Miele 7836 CD