Quantitative particle microscopy in self‐metered fluids

Abstract

SummaryWe describe a simple device that volumetrically samples poured liquids and draws buoyant materials into a single field of view for quantitative particle microscopy. Our approach relies on the formation of axisymmetric menisci and computational models of the static fluid developed using SURFACE EVOLVER showed close agreement with experiment. The apparatus was evaluated by counting pollen and demonstrated utility for the field analysis of microparticles.

Analysis of menisci formed on cones for single field of view parasite egg microscopy

“…These systems are undesirable for particle microscopy because particle beaching does not occur and the system is prone to shear indicating decreasing stability. This propensity to shear underpins an unmetered fluid loading approach (White et al ., ) and shows that at these volumes the governing dynamics of the droplet are dominated by gravity.…”

“…I–L) and presumably separated by a point of inflection, which shifts towards the well edge with the incremental reduction in volume. These observations are consistent with the previously observed system based on a hemispherical topology (White et al ., ).…”

“…In comparison to previous studies of the meniscus fluid–solid intersection points on hemispherical rod geometries (White et al ., ), we have demonstrated an intuitive mathematical analysis of the meniscus gradient. We have introduced a new rod geometry based on a cone and quantified the accuracy of our calculated meniscus gradients by measuring their deviation from the gradients extracted from profile images of menisci.…”

“…Single FOV imaging eliminates the need for lateral translation and offers a number of advantages including: raw digital electronic capture, computer assisted analysis, remote location processing, and the ability to archive and audit data (Mes et al ., ; Sowerby et al ., ; White et al ., ).…”

“…Single FOV imaging eliminates the need for lateral translation and offers a number of advantages including: raw digital electronic capture, computer assisted analysis, remote location processing, and the ability to archive and audit data (Mes et al, 2007;Sowerby et al, 2011;White et al, 2013). Mes et al (2007) first showed the elegant use of curved fluid interfaces (menisci) to facilitate single FOV imaging of parasite eggs caused to accumulate at an oil-water interface.…”