title: The application of scanning near field optical imaging to the study of human sperm morphology.
abstract: BACKGROUND
  The morphology of spermatozoa is a fundamental aspect to consider in fertilization, sperm pathology, assisted reproduction and contraception. Head, neck, midpiece, principal and terminal part of flagellum are the main sperm components to investigate for identifying morphological features and related anomalies. Recently, scanning near-field optical microscopy (SNOM), which belongs to the wide family of nanoscopic techniques, has opened up new routes for the investigation of biological systems. SNOM is the only technique able to provide simultaneously highly resolved topography and optical images with a resolution beyond the diffraction limit, typical of conventional optical microscopy. This offers the advantage to obtain complementary information about cell surface and cytoplasmatic structures.
  
  
  RESULTS
  In this work human spermatozoa both healthy and with morphological anomalies are analyzed by SNOM, to demonstrate the potentiality of such approach in the visualization of sperm morphological details. The combination of SNOM topography with optical (reflection and transmission) images enables to examine typical topographic features of spermatozoa together with underlying cytoplasmic structures. Indeed the head shape and inner components as acrosome and nucleus, and the organization of mitochondria in the midpiece region are observed. Analogously for principal tract of the tail, the ridges and the columns are detected in the SNOM topography, while their internal arrangement can be observed in the corresponding SNOM optical transmission images, without requiring specific staining procedures or invasive protocols.
  
  
  CONCLUSIONS
  Such findings demonstrate that SNOM represents a versatile and powerful tool to describe topographical and inner structural details of spermatozoa simultaneously. This analysis could be helpful for better characterizing several morphological anomalies, often related to sperm infertility, which cannot be examined by conventional techniques all together.
authors.affiliation: IOM-CNR, Area Science Park, Basovizza, Trieste, Italy. andolfi@iom.cnr.it.
authors.forename: Laura
authors.initials: L
authors.lastname: Andolfi
authors.affiliation: Department of Life Sciences University of Trieste, Trieste, Italy. etrevisan@units.it.
authors.forename: Elisa
authors.initials: E
authors.lastname: Trevisan
authors.affiliation: A.P.E. Research Srl, AREA Science Park, Basovizza, Trieste, Italy. barbara.troian@aperesearch.com.
authors.forename: Barbara
authors.initials: B
authors.lastname: Troian
authors.affiliation: A.P.E. Research Srl, AREA Science Park, Basovizza, Trieste, Italy. stefano.prato@aperesearch.com.
authors.forename: Stefano
authors.initials: S
authors.lastname: Prato
authors.affiliation: Institute for Maternal and Child Health, IRCCS Burlo Garofolo, Trieste, Italy. boscolo@burlo.trieste.it.
authors.forename: Rita
authors.initials: R
authors.lastname: Boscolo
authors.affiliation: Institute for Maternal and Child Health, IRCCS Burlo Garofolo, Trieste, Italy. elena.giolo@burlo.trieste.it.
authors.forename: Elena
authors.initials: E
authors.lastname: Giolo
authors.affiliation: Institute for Maternal and Child Health, IRCCS Burlo Garofolo, Trieste, Italy. stefania.luppi@burlo.trieste.it.
authors.forename: Stefania
authors.initials: S
authors.lastname: Luppi
authors.affiliation: Institute for Maternal and Child Health, IRCCS Burlo Garofolo, Trieste, Italy. monica_martinelli@hotmail.it.
authors.forename: Monica
authors.initials: M
authors.lastname: Martinelli
authors.affiliation: Institute for Maternal and Child Health, IRCCS Burlo Garofolo, Trieste, Italy. giuseppe.ricci@burlo.trieste.it.|Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy. giuseppe.ricci@burlo.trieste.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ricci
authors.affiliation: Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy. zweyer@units.it.
authors.forename: Marina
authors.initials: M
authors.lastname: Zweyer
mesh_terms: D053713:Azoospermia / Q000473:pathology; D004867:Equipment Design; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008853:Microscopy / Q000295:instrumentation* / Q000379:methods*; D055100:Optical Fibers; D013094:Spermatozoa / Q000166:cytology* / Q000473:pathology / Q000502:physiology