Cyto 2011—Overview of the XXVI ISAC Congress Proceedings Issue of Cytometry

Abstract

THIS issue of Cytometry presents the third occasion on which a call has been issued to encourage authors to submit their work to the journal for publication as part of a special Congress Proceedings Issue of Cytometry. An incentive for submission was that accepted papers would be guaranteed an oral presentation at the XXVI ISAC Congress in Baltimore—CYTO 2011. The topics of the accepted papers range from proteomewide modeling to CD4 testing in resource-limited settings. The research articles do not speak to a given theme, rather they provide a snap-shot of the diversity of interest in cytometry with proffered examples of some of the latest trends in the field of cytometry. The Proceedings Issue of Cytometry also incorporates two reviews. The first review, by Darzynkiewicz et al., has been scheduled for publication in alignment with the conference, as it speaks to a topical area—‘‘click chemistry’’—an increasingly used conjugation and assembly technology with attendant advantages of biocompatibility, selectivity, and yield (1). The second review, presented at CYTO 2011, provides an update on cytometric challenges in veterinary andrology. In parallel with the discovery of the structure of DNA, 1953 also saw the publication of a study by Howard and Pelc (2) on the patterns of radiolabel incorporation by meristematic cells of Vicia faba. This landmark paper proposed the existence of a cell division cycle demarcated by preand postgaps for DNA synthesis. Their discovery set in process the widespread application of labeling methods for the analysis of the eukaryotic cell cycle, leading to the recognition of the universality of its major regulators (3) and exploitation in studies on anticancer drug-induced perturbations of cell cycle kinetics. In this issue, Darzynkiewicz et al. overview the Cytometry of DNA replication and RNA synthesis from its historical backdrop to recent advances based on ‘‘Click Chemistry.’’ The review covers fluorescence quenching methods, immunocytochemical detection through to the recent incorporation of EdU for the click chemistry detection of DNA damage via histone H2AX phosphorylation analyzed by flow or laser scanning cytometry. K.B. Sharpless, the 2001 Nobel Prize winner for Chemistry, introduced the concept of click chemistry for reactions that fulfill useful criteria including being modular and providing very high yields with favored physiologically stable, single reaction products (4). The concept drives applications for addition reaction conditions using preferred solvents and simple routes for product isolation— key issues for the cytometrist. Since the first reports of sexed sperm, flow technology efforts have been largely focused on improving sample throughput resulting in routine high-purity sorting of Xor Y-chromosome-bearing sperm (5). However, a more refined assessment of fertilizing potential of veterinary semen samples by flow cytometry has yet to exploit the full potential of the technology. Petrunkina and Harrison in Cambridge, UK have worked on the determinants of sperm quality and fertility in domestic species and recently provided an exact mathematical analysis of the systematic mis-estimation of semen-derived cell subpopulations by flow cytometry (6). The current review addresses cytometric solutions presenting recent developments, advantages and limitations together with the aspects of sperm physiology that could benefit from multicolor flow cytometric procedures. Advantageous biophotonic characteristics of molecular probes underpin many cytometric studies. The detection of lu-