title: Magnetic Alignment of Microelements Containing Cultured Neuronal Networks for High-Throughput Screening.
abstract: High-throughput screening (HTS) on neurons presents unique difficulties because they are postmitotic, limited in supply, and challenging to harvest from animals or generate from stem cells. These limitations have hindered neurological drug discovery, leaving an unmet need to develop cost-effective technology for HTS using neurons. Traditional screening methods use up to 20,000 neurons per well in 384-well plates. To increase throughput, we use "microraft" arrays, consisting of 1600 square, releasable, paramagnetic, polystyrene microelements (microrafts), each providing a culture surface for 500-700 neurons. These microrafts can be detached from the array and transferred to 384-well plates for HTS; however, they must be centered within wells for automated imaging. Here, we developed a magnet array plate, compatible with HTS fluid-handling systems, to center microrafts within wells. We used finite element analysis to select an effective size of the magnets and confirmed that adjacent magnetic fields do not interfere. We then experimentally tested the plate's centering ability and found a centering efficiency of 100%, compared with 4.35% using a flat magnet. We concluded that microrafts could be centered after settling randomly within the well, overcoming friction, and confirmed these results by centering microrafts containing hippocampal neurons cultured for 8 days.
authors.affiliation: UNC/NCSU Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill and Raleigh, NC.
authors.forename: Kent R
authors.initials: KR
authors.lastname: Gordon
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC.
authors.forename: Yuli
authors.initials: Y
authors.lastname: Wang
authors.affiliation: UNC/NCSU Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill and Raleigh, NC Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC.
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Allbritton
authors.affiliation: UNC/NCSU Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill and Raleigh, NC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC Carolina Institute for Developmental Disabilities, Carrboro, NC amtaylor@unc.edu.
authors.forename: Anne Marion
authors.initials: AM
authors.lastname: Taylor
mesh_terms: D000818:Animals; D002470:Cell Survival; D002478:Cells, Cultured; D004353:Drug Evaluation, Preclinical; D057166:High-Throughput Screening Assays / Q000295:instrumentation* / Q000379:methods; D060328:Magnetic Phenomena; D009415:Nerve Net / Q000166:cytology; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D017207:Rats, Sprague-Dawley
keywords: finite element analysis; high-throughput screening; magnetic centering; microfabrication; microraft arrays; primary neurons