Why is ammonium oxalate added to blood samples before performing platelet counts?

Ammonium oxalate is commonly used in blood sample processing specifically for its ability to lyse red blood cells. When ammonium oxalate is added to a blood sample, it interacts with the red blood cells and causes them to rupture, releasing hemoglobin into the solution. This lysing effect is crucial during platelet counting because it helps to eliminate interference from the red blood cells that could skew the results. By removing the red blood cells, the focus can be shifted solely to the platelets, thus providing a more accurate platelet count.

In the context of testing, it's essential to ensure that red blood cells do not affect the visibility and counting of platelets, as their presence can complicate the analysis and lead to inaccurate results. Therefore, the addition of ammonium oxalate plays a vital role in obtaining precise measurements of platelet concentration in blood samples.