The most accurate tests of bacterial content suprapubic aspiration (children less than 2 year of age) and properly performed bladder catheterization (as long as the first few milliliters are excluded from collection). Care of a urine specimen obtained for culture is an important nursing responsibility related to diagnosis. The specimen should be taken to the laboratory for culture immediately. If culture is delayed, the sample can result in a loss of formed elements. Such as blood cells and casts.