title: Micro-electrophoresis: a noninvasive method of sperm selection based on membrane charge.
abstract: OBJECTIVE
  To develop a technique with the potential of isolating genetically fit sperm for assisted reproductive technology (ART) treatment without compromising its structural or functional competence.
  
  
  METHODS
  Observational study.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Fifty patients undergoing infertility diagnosis and 88 couples undergoing ART treatment.
  
  
  METHODS
  None.
  
  
  METHODS
  Under an electric field, the percentage of positively charged sperm (PCS), negatively charged sperm (NCS), and neutrally charged sperm was determined for each ejaculate before and after density gradient centrifugation (DGC), and evaluated for sperm DNA damage, histone retention, and couples' ART outcomes. Subsequently, PCS, NCS, and neutrally charged sperm were selected using an intracytoplasmic sperm injection needle and directly analyzed for DNA damage.
  
  
  RESULTS
  There was a reduction in the NCS population (95.10% ± 0.94% vs. 54.48% ± 2.39%) and an increase in the PCS population (4.28% ± 0.58% vs. 42.52% ± 2.36%) after DGC. The DNA damage was inversely proportional to %NCS (r(2) = -0.242) and directly proportional to the %PCS (r(2) = 0.206). When sperm were picked according to their charge and directly analyzed, sperm DNA damage was lower in the NCS population (3.9% ± 1.5%) compared with control (17.3% ± 3.2%) and %PCS populations (27.8% ± 6.0%). The %NCS was positively associated with fertilization rate (r(2) = 0.469) and blastocyst development (r(2) = 0.308) and inversely associated with embryo arrest (r(2) = -0.253). Implantation rate and clinical pregnancies were higher in patient groups with increased NCS.
  
  
  CONCLUSIONS
  Selection of NCS through micro-electrophoresis has the potential to isolate sperm relatively free of DNA damage to be used in ART.
authors.affiliation: Andrology and IVF Laboratory, Department of Surgery (Urology), University of Utah, Salt Lake City, Utah.
authors.forename: Luke
authors.initials: L
authors.lastname: Simon
authors.affiliation: Andrology and IVF Laboratory, Department of Surgery (Urology), University of Utah, Salt Lake City, Utah.
authors.forename: Kristin
authors.initials: K
authors.lastname: Murphy
authors.affiliation: Andrology and IVF Laboratory, Department of Surgery (Urology), University of Utah, Salt Lake City, Utah.
authors.forename: Kenneth I
authors.initials: KI
authors.lastname: Aston
authors.affiliation: Andrology and IVF Laboratory, Department of Surgery (Urology), University of Utah, Salt Lake City, Utah.
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Emery
authors.affiliation: Andrology and IVF Laboratory, Department of Surgery (Urology), University of Utah, Salt Lake City, Utah.
authors.forename: James M
authors.initials: JM
authors.lastname: Hotaling
authors.affiliation: Andrology and IVF Laboratory, Department of Surgery (Urology), University of Utah, Salt Lake City, Utah; Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, Utah; Department of Human Genetics, University of Utah, Salt Lake City, Utah. Electronic address: douglas.carrell@hsc.utah.edu.
authors.forename: Douglas T
authors.initials: DT
authors.lastname: Carrell
mesh_terms: D000328:Adult; D002462:Cell Membrane / Q000378:metabolism*; D004586:Electrophoresis / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy; D027724:Reproductive Techniques, Assisted; D055101:Semen Analysis / Q000379:methods*; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods; D013094:Spermatozoa / Q000378:metabolism*
keywords: ART outcomes; histone retention; micro-electrophoresis; sperm DNA damage; sperm selection