Final answer:
The yellow tinge in plasma in a microhematocrit tube indicates 'icteric' plasma, which is associated with an increased concentration of bilirubin and is a characteristic of jaundice or icterus.
Step-by-step explanation:
Plasma that appears yellow tinged in a spun microhematocrit tube is referred to as icteric. This yellow discoloration is due to the accumulation of hemoglobin degradation products, such as bilirubin, in the blood. When the concentration of bilirubin increases in the blood, it can diffuse into peripheral tissues, causing them to appear yellow, a condition known as jaundice or icterus. This manifestation is not to be confused with hemolyzed, which indicates the breakdown of red blood cells; lipemic, which indicates a high concentration of lipids in the blood; or polycythemia, which is an elevated level of hemoglobin or red blood cells.
A spun microhematocrit tube is used to measure the percentage of red blood cells (erythrocytes) in a blood sample. When the plasma in the tube appears yellow tinged, it is referred to as icteric. This discoloration can indicate jaundice or icterus, which is caused by the accumulation of bile pigments in the blood due to liver dysfunction. The yellowish color is a result of the diffusion of bilirubin into the tissues.