Urine sample in kidneys

 24-hour urine protein test checks the function of the kidneys and detects disease. Urine samples are collected in one or more containers over a period of 24 hours. The containers are kept in a cool environment and then sent to a lab for analysis. Specialists then check the urine for protein. The test is simple and noninvasive.

Good use of Google there I suppose MG, although I'm not sure it answers the question...With many tests that look at bodily functions they should be repeated to see if and how results change over a period of time, since our bodies change multiple times during the day, and even throughout the week depending on what we're doing, eating, drinking, feeling. I'd imagine that more proteins and amino acids would be excreted from the kidneys some time after meals as they're digested and absorbed into the blood stream, but if they are consistently high this might be cause for concern, as it might indicate kidney disease or damage, or other problems such as diabetes or urinary tract infections (UTIs).According to Healthline (where the previous answer is copied from) more protein is excreted during the day than in the nighttime. If the test is only done in the morning let's say, then protein levels will be low in the urine because the body has been at rest, and so levels may be in the normal range even though the patient might have kidney damage, which would therefore go undetected. Therefore it is sensible to do the test again in the evening when levels of protein will be high, to see if the levels are still within normal limits, or if they exceed what's healthy. Of course if levels are high in the morning when they should be low this would be an instant warning sign to medical professionals.Hope this helps!

It checks the function of the kidneys and detects disease. Too much protein can be a sign of kidney damage or disease. It can test for uncontrolled diabetes, high blood pressure, lupus orUrinary tract infections Also protein levels may be higher during the day than at night. 

this is the answer you require:Over the course of a 24-hour period, the composition and concentration of urine changes continuously. For this reason, various types of specimens may be collected, including:First morning specimenSingle random specimenTimed short-term specimensTimed long term specimens: 12 or 24 hoursCatheterized specimen or specimen from an indwelling catheterDouble voided specimens (test for sugar and acetone)Clean-catch (midstream) specimen for urine culture and cytological analysesThe first voided morning specimen is particularly valuable because it is more concentrated and abnormalities are easier to detect. An early morning specimen is also relatively free of dietary influences and changes due to physical activity. In collecting any urine specimen, it is always important for the nurse to observe specific agency protocols, to check with the laboratory regarding the need for refrigeration or preservation of specimens, and to follow universal precautions. Single random specimens may be taken at any time of the day or night. Timed specimens range from short-term 2-hour collections to 24-hour collections.A 24-hour urine specimen is an extremely important diagnostic test because it reveals how the kidney adjusts to changing physiologic needs over a long period. Substances excreted by the kidney are not excreted at the same rate or in the same amounts during different periods of day and night; therefore, a random urine specimen does not accurately represent the processes taking place over a 24-hour period. However, a 24-hour urine specimen is useful only when all the patient's urine is collected for 24 hours. Even if just one sample is discarded, the results will be inaccurate. The nurse must ensure that the patient and all assistive personnel understand the importance of saving all the urine. To begin the 24-hour collection, the person voids and discards the urine already in the bladder. All urine starting with the next voiding is collected for the next 24 hours and put into a large collection bottle. To prevent breakdown of urinary components, the collection has a preservative added to it or is refrigerated.