Streck’s STaK-Chex Plus Retics is a five-part differential control that monitors all parameters, including reticulocytes and nucleated red blood cells, for the Beckman Coulter UniCel DxH 600 and 800, LH 780/785, LH 750/755, LH 500, and HmX instruments. The three-level assay contains white blood cell types, reticulocytes, and nucleated red blood cells that are within clinically significant ranges. The controls are available in plastic cap-pierceable vials that allow for autosampling by an analyzer. The product is stable for 105 days closed-vial and 14 days open-vial.