title: Localized measurements of physical parameters within human sperm cells obtained with wide-field interferometry.
abstract: We developed a new method to identify the separate cellular compartments in the optical path delay (OPD) maps of un-labeled spermatozoa. This was conducted by comparing OPD maps of fixed, un-labeled spermatozoa to bright field images of the same cells following labeling. The labeling enabled us to identify the acrosomal and nuclear compartments in the corresponding OPD maps of the cells. We then extracted the refractive index maps of fixed cells by dividing the OPD maps of spermatozoa by the corresponding thickness maps of the same cells, obtained with AFM. Finally, the dry mass of the head, nucleus and acrosome of un-labeled immobile spermatozoa, was measured. This method provides the ability to quantitatively measure the dry mass of cellular compartments within human spermatozoa. We expect that these measurements will assist label-free selection of sperm cells for fertilization.
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Michal
authors.initials: M
authors.lastname: Balberg
authors.affiliation: Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel.
authors.forename: Mattan
authors.initials: M
authors.lastname: Levi
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Ksawery
authors.initials: K
authors.lastname: Kalinowski
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Itay
authors.initials: I
authors.lastname: Barnea
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Simcha K
authors.initials: SK
authors.lastname: Mirsky
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Natan T
authors.initials: NT
authors.lastname: Shaked
mesh_terms: D000177:Acrosome / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D006801:Humans; D007368:Interferometry; D008297:Male; D008853:Microscopy; D013094:Spermatozoa / Q000166:cytology*
keywords: digital holography; dry mass; interferometric phase microscopy; sperm morphology