Comparative efficacy of medical instrument cleaning products in digesting some blood proteins

Abstract

The instrument-cleaning step is recognised as critical in achieving sterility or high-level disinfection in the medical instrument reprocessing cycle. Proteins in the residual bioburden on instruments after their use present a serious challenge to successful reprocessing, as they can adversely affect both chemical and physical sterilisation. The commercial products used in the cleaning step have a variety of functionalities, one of the most important of which is the elimination of human proteins from the instrument prior to the sterilisation/high level disinfection step. The methodology employed in this study is SDS-PAGE, a gel electrophoresis technique, which is a standard for determining protein molecular weights. Some proteins have low water-solubility and can be reliably eliminated only when broken down into small water-soluble fragments. The study involves the comparison of protein molecular weights before and after treatment with various cleaning products to give a clear indication of protein digestion efficacy. The study concludes that many products claiming protein digestion properties have virtually no efficacy in this regard, whilst others tested are highly effective. This is alarming since most of the products tested claim 'removal of all proteins' within two minutes.