bioAffinity Technologies 2 articles published in JoVE Chemistry Porphyrin-Modified Beads for Use as Compensation Controls in Flow Cytometry William Bauta1, Marcia Grayson1, Rossella Titone1, Jennifer Rebeles1, Vivienne I. Rebel1 1bioAffinity Technologies The protocol describes how porphyrin-based compensation beads for flow cytometry are prepared by the reaction of amine-functionalized polystyrene beads with the porphyrin TCPP and the amide coupling reagent EDC. A filtration procedure is used to reduce the particulate byproducts. Medicine Quality-Controlled Sputum Analysis by Flow Cytometry Marcia Grayson*1, Shao-Chiang Lai*1, Lydia H. Bederka1, Patricia Araujo1, Jamila Sanchez1, Xavier T. Reveles1, Vivienne I. Rebel1,2, Jennifer Rebeles1 1bioAffinity Technologies, 2Department of Cell Systems & Anatomy, The University of Texas Health Science Center at San Antonio This protocol describes an efficient method for dissociating sputum into a single cell suspension and the subsequent characterization of cellular subsets on standard flow cytometric platforms.