The most reliable urine specimen is obtained by-

• Most often, the urine is often obtained from a voided specimen. • In children who are not toilet trained, a urine collection device, such as a bag, is placed over the genitalia, and the urine is cultured from the bagged specimen. • Suprapubic aspiration avoids potential contamination; however, due to its invasiveness, it is rarely used except in children and selected patients. • Urine obtained from a urinary catheter is less invasive than a suprapubic aspiration and is less likely to be contaminated than that from a voided specimen.