Final answer:
The first step in the midstream clean-catch method is using aseptic technique to protect the urine sample from potential contamination.
Step-by-step explanation:
The first step in the midstream clean-catch method involves aseptic technique to prevent contamination of the urine sample which could alter the results of the urinary analysis. In a clinical or laboratory setting, this procedure typically starts with thorough hand-washing followed by cleaning the genital area with an antiseptic wipe to reduce the presence of bacteria that normally reside on the skin. Once the area is cleaned, the individual begins to urinate, stops momentarily (midstream), and then collects the urine sample in a sterile container. This is considered the 'clean-catch' portion, as the initial flow of urine helps to cleanse the urethra of any contaminants that could skew the bacteria count in the urine culture.