I cannot drop any names but would not say I have this info without knowing first hand. Sediments do hurt the sample as they are looked for in the tests and are signs of beginning bacteria formation. You can get the information regarding this off of most web sites that sell urine. Collection for the companies usualy consists of a specific donor or the owner peeing in an old water jug and storing it in the refrigerator until it is packaged and frozen. Urine can usualy last 3-4 days not frozen and when accepted in large quantities (gallons) by a donor can sit 3 days in a refrigerator before sitting again and waiting to be packaged then frozen. this is what can cause a problem. Even with out the actual info, this is common sense. If they get from a donor there is going to be a time laps and urine does form bacteria over time.