Why is it important to avoid contamination during protein purification?

Avoiding contamination during protein purification is crucial because contaminants can significantly affect the activity and effectiveness of the purified protein, as well as the accuracy of experimental results. When proteins are purified from a biological source, such as bacteria or animal tissues, the presence of unwanted substances—like other proteins, nucleic acids, or small molecules—can lead to misleading conclusions. For instance, if a contaminant has similar properties to the target protein, it might interfere with assays designed to measure the protein's activity or function, leading to incorrect data interpretation. Ensuring high purity is necessary for reliable experiments, as it allows researchers to attribute observed effects specifically to the protein of interest without the confounding influence of contaminants.