Streck offers the CD-Chex TdT Plus, a flow cytometry control assayed for TdT, CD1a, CD34, and cCD3 in a single control. CD-Chex TdT Plus can be used as quality control material for evaluating intracellular and surface antigens, including CD1a, CD2, CD4, CD5, CD7, CD8, CD34, cytoplasmic CD3, and nuclear TdT (terminal deoxynucleotidyl transferase). The assays are designed for BD Biosciences and Beckman Coulter flow cytometry systems, with 30-day open-vial stability and up to 90-day closed-vial stability.