Final answer:
Prolonged urine storage can lead to a decrease in pH and protein concentration, and an increase in specific gravity due to the evaporation of water and the concentration of solutes.
Step-by-step explanation:
Effect of Prolonged Urine Storage on Urinalysis
Urinalysis is often affected by prolonged urine storage, which can alter various parameters of the urine being tested. One of the changes that can occur is the decrease in pH of the urine over time. When urine is stored for prolonged periods, the breakdown of urea to ammonia by bacteria can raise the pH, but over an extended period, the eventual loss of carbon dioxide and the consumption of the buffer systems can lead to a lower pH. Another change includes an increase in specific gravity due to the evaporation of water, which concentrates the urine more. However, when considering protein concentration, one might observe a decreased protein concentration as proteins may degrade over time or be consumed by bacteria.
Specific gravity is an important measure in urinalysis that indicates the concentration of solutes in the urine. It is affected by the temperature and can be measured using a urinometer. The specific gravity normally increases when the urine is more concentrated, such as when the kidney is reabsorbing more filtered water due to a substance like ADH. If the ability of the kidneys to concentrate or dilute urine, measured by osmolality, is compromised, this could indicate decreased kidney function.