Final answer:
The dilution effect in microsampling is due to the mix of tissue fluids and blood when a blood vessel is severed during an injury.
Step-by-step explanation:
Forgetting to wipe away the first drop of blood during microsampling can cause erroneous lab results due to dilution by tissue fluids that may have mixed with the blood. When a blood vessel is severed, as in an injury, not only blood but also different components leak out.
These include not just red and white blood cells, but also interstitial fluid, which is the fluid that bathes and surrounds the tissue cells. This fluid can dilute the blood sample collected, leading to inaccurate measurements and lab results. It is imperative for medical workers to ensure that the first drop of blood, which might be contaminated with tissue fluids, is wiped away to avoid this issue and maintain the integrity of the blood sample.