Accurate urine sample collection is a straightforward procedure that directly influences the reliability of diagnostic testing. The primary goal of this technique is to prevent contamination from bacteria naturally present on the skin and genitals. Contamination can lead to inaccurate results, potentially causing misdiagnosis or unnecessary treatment, especially when testing for a urinary tract infection (UTI). Following a standardized procedure ensures the specimen truly reflects the contents of the bladder.
Preparing for Collection
Before starting, gather all necessary supplies and review the instructions provided by the clinic or lab. The collection container must be sterile and specifically provided for this purpose; do not use a household container, as this can introduce contaminants. Ensure the sterile cup and any provided cleansing towelettes are within easy reach before starting.
Thorough handwashing with soap and water is the first step in minimizing the risk of introducing external bacteria. Wash your hands for at least 20 seconds, paying attention to the nail beds and between the fingers, and dry them on a clean towel. With clean hands, open the sterile cup and place the lid on a clean, flat surface with the inside facing up. Take care not to touch the inner surface of the lid or the cup itself.
A second identifier is a laboratory standard used to ensure the sample is correctly matched to the patient record. Confirm that the patient’s name and a second unique identifier, such as a date of birth or medical record number, are ready to write on the label. This double-check system reduces the chance of administrative errors that could delay diagnosis.
Executing the Clean-Catch Method
The clean-catch method is a technique designed to isolate the midstream urine, bypassing the first flow which flushes bacteria from the urethra and surrounding skin. This technique involves anatomical cleansing followed by a specific voiding sequence. The cleansing process differs slightly based on anatomy, but the underlying principle is the same: to reduce the normal bacterial flora around the urinary opening.
Female Cleansing
For individuals with female anatomy, the cleaning process requires separating the labia with one hand. Using the provided towelette, wipe the area from front to back in a single motion, then discard the used towelette. Repeat the action with a new towelette if multiple are provided. Continue holding the labia apart throughout the entire collection process to prevent contamination.
Male Cleansing
For individuals with male anatomy, cleansing involves wiping the tip of the penis with the provided towelette. If uncircumcised, the foreskin must be retracted before wiping and held back during the entire collection. This prevents bacteria from entering the sample stream, and the towelette should be immediately discarded.
Midstream Collection
The actual collection begins by voiding a small amount of urine directly into the toilet. This initial flow, approximately one to two seconds, flushes out any remaining bacteria or cells from the lower urethra. Without stopping the flow, carefully bring the sterile cup into the stream to catch the middle portion, known as the “midstream.”
Fill the cup until it is about half full, or to the level indicated by the laboratory (typically 30 to 60 milliliters). Ensure the cup does not touch the genital area, the toilet, or the inner thigh during this process, as contact can re-contaminate the sample. Once the necessary amount is collected, remove the cup from the stream and finish voiding the rest of the urine into the toilet.
Handling and Submission
Once the midstream sample is collected, immediately seal the container tightly with the cap, touching only the outer surfaces of the cup and lid. A secure seal prevents leakage and exposure to external contaminants during transport. Immediately after sealing, the cup must be labeled clearly with the patient’s full name, the date, and the exact time of collection.
Accurate labeling is required, as mislabeled or unlabeled specimens are commonly rejected by the laboratory, requiring the collection process to be repeated. If a second unique identifier, such as a medical record number or date of birth, is required, ensure that information is also clearly written on the label. The time of collection is important because the viability of the sample can quickly degrade.
The integrity of the urine sample is highly dependent on temperature and time; bacterial overgrowth can occur rapidly at room temperature, leading to false-positive results. If submitting the sample immediately, aim to deliver it to the lab or clinic within one to two hours of collection. If a delay is unavoidable, the sample must be refrigerated at approximately 39 degrees Fahrenheit (4 degrees Celsius) to slow bacterial multiplication. Refrigeration can preserve the sample for up to 24 hours, but prompt submission is always preferred for the most accurate results.