What is an anticoagulant that prevents platelets from clumping and preserves the appearance of blood cells for microscopic preparation?

An anticoagulant that prevents platelets from clumping and preserves the appearance of blood cells for microscopic preparation is EDTA (ethylenediaminetetraacetic acid). EDTA works by chelating calcium ions, which are essential for the coagulation process, thereby inhibiting clot formation. This property helps maintain the integrity of blood cells, making it suitable for laboratory analysis and microscopic examination.