Abstract 1869: Using Nanoparticle Tracking Analysis (NTA) to characterize cellular microvesicles

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Cellular microvesicles (100 nm-1µm) are shed into the circulation from many different cell types including; platelets, erythrocytes and endothelial cells. They have major potential as novel biomarkers as they have been shown to be implicated in a multitude of pathological conditions. However, developments in this area are constrained by limitations in the technology available for their measurement. Nanoparticle Tracking Analysis (NTA) (NanoSight Ltd, Amesbury) offers the potential to both enumerate and speciate (through fluorescent markers) these microparticles in a rapid manner. In this method a laser beam passes through a suspension at a low angle. The particles scatter light which is collected onto a CCD (or sCMOS) camera by a microscope-type configuration. Particles between 10-2000 nm are tracked individually and their diffusion coefficient, and therefore size, calculated directly from their speed. Therefore, this characterization method gives a direct measurement of the concentration and size distribution of the particles in the field of view. If the particles are fluorescently labelled, then the concentration and size distribution are those of the labelled particles only, allowing a proportion of labelled particles to be calculated. However, this requires a combination of aspects to be identified and optimised during the process. This talk will look at some of the challenges and considerations that need to be taken during the protocol development and measurement. It will also review the application of the technique in this field, compare and contrast it to other applicable technologies such as various forms of electron microscopy (EM) and to flow cytometry. Citation Format: Sonja Capracotta, Pauline Carnell, Andrew Malloy, Patrick Hole, Bob Carr. Using Nanoparticle Tracking Analysis (NTA) to characterize cellular microvesicles. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1869. doi:10.1158/1538-7445.AM2014-1869