title: Flow speed alters the apparent size and concentration of particles measured using NanoSight nanoparticle tracking analysis.
abstract: Nanoparticle tracking analysis (NTA) is commonly used to count and size nano-sized particles. A sample loading pump can be used to analyse a larger sample volume, but it is unclear whether accuracy is affected. Using a NanoSight NS300 with the manufacturer-supplied pump, we examined synthetic silica and latex microspheres, liposomes and placental extracellular vesicles at different flow speeds. Analysis at flow speeds of 20 or 50 significantly reduced the measured concentration and mean/modal size of particles, particularly for mono-dispersed samples. We identify sample flow speed as a crucial instrument setting which should be reported in all studies that use NTA.
authors.affiliation: Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, 1142, New Zealand. Electronic address: mancy.tong@auckland.ac.nz.
authors.forename: M
authors.initials: M
authors.lastname: Tong
authors.affiliation: Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, 1142, New Zealand. Electronic address: obro682@aucklanduni.ac.nz.
authors.forename: O S
authors.initials: OS
authors.lastname: Brown
authors.affiliation: Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, 1142, New Zealand; Maternal Fetal Medicine, Auckland City Hospital, New Zealand. Electronic address: p.stone@auckland.ac.nz.
authors.forename: P R
authors.initials: PR
authors.lastname: Stone
authors.affiliation: Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, 1142, New Zealand. Electronic address: l.cree@auckland.ac.nz.
authors.forename: L M
authors.initials: LM
authors.lastname: Cree
authors.affiliation: Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, 1142, New Zealand. Electronic address: l.chamley@auckland.ac.nz.
authors.forename: L W
authors.initials: LW
authors.lastname: Chamley
mesh_terms: D058948:Cell Tracking / Q000379:methods; D000067128:Extracellular Vesicles / Q000737:chemistry / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D008081:Liposomes / Q000032:analysis / Q000737:chemistry; D008863:Microspheres; D009068:Movement; D053758:Nanoparticles / Q000032:analysis*; D010316:Particle Size; D010920:Placenta / Q000737:chemistry / Q000166:cytology / Q000648:ultrastructure*; D011247:Pregnancy; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D008081:Liposomes; D012822:Silicon Dioxide
keywords: Exosomes; Liposome; Nanoparticle tracking analysis; Nanoparticles; Vesicle