Scalable Conjugation and Characterization of Immunoglobulins with Stable Mass Isotope Reporters for Single-Cell Mass Cytometry Analysis.

The advent of mass cytometry (CyTOF) has permitted simultaneous detection of more than 40 antibody parameters at the single-cell level, although a limited number of metal-labeled antibodies are commercially available. Here we present optimized and scalable protocols for conjugation of lanthanide as well as bismuth ions to immunoglobulin (Ig) using a maleimide-functionalized chelating polymer and for characterization of the conjugate. The maleimide functional group is reactive with cysteine sulfhydryl groups generated through partial reduction of the Ig Fc region.

Assessing basophil activation by using flow cytometry and mass cytometry in blood stored 24 hours before analysis.

Background: Basophil activation tests (BATs) have promise for research and for clinical monitoring of patients with allergies. However, BAT protocols vary in blood anticoagulant used and temperature and time of storage before testing, complicating comparisons of results from various studies.

Objective: We attempted to establish a BAT protocol that would permit analysis of blood within 24 hours of obtaining the sample.