What are potential problems associated with using EDTA anticoagulant and holding the blood too long?

Using EDTA as an anticoagulant can indeed lead to several issues when blood samples are held for an extended period before analysis. One significant concern is that prolonged storage can result in changes in parasite morphology. This is critical because accurate diagnosis of parasitic infections often relies on the visible characteristics of the parasites under a microscope. Morphological changes can make identification challenging and may lead to diagnostic errors.

Additionally, the use of EDTA can result in poor staining of blood smears. Staining is a vital step in the examination of blood samples because it enhances the visibility of cellular components, including parasites. If samples are stored too long, the integrity of the cells can degrade, leading to suboptimal staining results that hinder diagnostic interpretation.

Moreover, specific features like Schüffner's dots, which are associated with certain malaria parasites, could be lost over time. These dots are important for accurate identification and classification of the species of plasmodium. If they are compromised due to storage conditions or prolonged time, it complicates the diagnosis significantly.

In summary, using EDTA and holding blood samples for too long affects both the morphology of parasites and the quality of staining, leading to diagnostic challenges that can severely impact patient care and research.