title: Experimental evidence of a buoyant mass difference between bovine spermatozoa bearing X- and Y-chromosomes using a micromechanical resonator.
abstract: Flow cytometry is to date the only commercially viable technique for sex preselection of mammalian spermatozoa, measuring the different DNA content in X- and Y-chromosome bearing spermatozoa. Here we present experimental evidence of a measurable difference between bovine spermatozoa bearing X- and Y-chromosomes based on their buoyant mass. Single cells of two populations of flow-cytometrically sorted spermatozoa were analyzed by means of a micromechanical resonator, consisting of a suspended doubly-clamped microcapillary. Spermatozoa buoyant mass is related to the transitory variation in vibration phase lag, caused by the passage through the sensitive area of a single sperm cell suspended in a fluid. Data analysis shows two well-separated distributions and provides evidence of the sensor capabilities to detect the buoyant mass of single cells with such accuracy to distinguish X- and Y-chromosome bearing spermatozoa. These preliminary results suggest the possibility to develop an intriguing technique alternative to flow cytometry in the field of sperm sorting.
authors.affiliation: Novaetech S.r.l., Via J. F. Kennedy n.5, 80125, Napoli, Italy. mauro@novaetech.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Mauro
authors.forename: Raffaele
authors.initials: R
authors.lastname: Battaglia
authors.forename: Gianluca
authors.initials: G
authors.lastname: Ferrini
authors.forename: Roberto
authors.initials: R
authors.lastname: Puglisi
authors.forename: Donatella
authors.initials: D
authors.lastname: Balduzzi
authors.forename: Andrea
authors.initials: A
authors.lastname: Galli
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology; D002417:Cattle; D008297:Male; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D012743:Sex Preselection / Q000379:methods*; D013094:Spermatozoa / Q000502:physiology*; D014960:X Chromosome / Q000502:physiology*; D014998:Y Chromosome / Q000502:physiology*