CRCST Practice Exam 2026 - Free CRCST Practice Questions and Study Guide

Protease enzymes are specifically designed to break down proteins, which are a significant component of heavy soil found on surgical instruments. These enzymes cleave the peptide bonds in protein molecules, leading to their degradation into smaller peptides and amino acids. In a sterile processing environment, heavy soil may consist of blood, tissue, and other organic materials that are primarily protein-based. By utilizing protease enzymes, cleaning products can effectively break down these stubborn deposits, allowing for easier removal during the cleaning process.

Lipase enzymes, which break down fats, and amylase enzymes, which focus on carbohydrates, are important for other types of soil but are not primarily effective against the protein-based contaminants common in surgical instruments. Lactase is an enzyme that digests lactose, the sugar found in milk, and is not relevant in the context of instrument cleaning. Therefore, protease enzymes are the most appropriate choice for addressing heavy soil on instruments.