Nanoparticle suspensions enclosed in methylcellulose: a new approach for quantifying nanoparticles in transmission electron microscopy

Christian Hacker, Jalal Asadi, Christos Pliotas, Sophie Grace Alicia Ferguson, Lee Sherry, Phedra Marius, Javier Tello, David Jackson, James Henderson Naismith, John Milton Lucocq

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)
7 Downloads (Pure)

Abstract

Nanoparticles are of increasing importance in biomedicine but quantification is problematic because current methods depend on indirect measurements at low resolution. Here we describe a new high-resolution method for measuring and quantifying nanoparticles in suspension. It involves premixing nanoparticles in a hydrophilic support medium (methylcellulose) before introducing heavy metal stains for visualization in small air-dried droplets by transmission electron microscopy (TEM). The use of methylcellulose avoids artifacts of conventional negative stain-TEM by (1) restricting interactions between the nanoparticles, (2) inhibiting binding to the specimen support films and (3) reducing compression after drying. Methylcellulose embedment provides effective electron imaging of liposomes, nanodiscs and viruses as well as comprehensive visualization of nanoparticle populations in droplets of known size. These qualities facilitate unbiased sampling, rapid size measurement and estimation of nanoparticle numbers by means of ratio counting using a colloidal gold calibrant. Specimen preparation and quantification take minutes and require a few microliters of sample using only basic laboratory equipment and a standard TEM.
Original languageEnglish
Article number25275
Number of pages13
JournalScientific Reports
Volume6
DOIs
Publication statusPublished - 4 May 2016

Keywords

  • Electron microscopy
  • Liposome
  • Methylcellulose
  • Nanoparticles
  • Negative stain
  • Quantification
  • Stereology
  • Virus

Fingerprint

Dive into the research topics of 'Nanoparticle suspensions enclosed in methylcellulose: a new approach for quantifying nanoparticles in transmission electron microscopy'. Together they form a unique fingerprint.

Cite this