Fig 1.
A microfiltration device for trapping and analysis of Schistosoma haematobium eggs.
(A) Schematic of the microfiltration device. (B) Schematic representation of the experimental setup with a syringe pump withdrawing fluid from the outlet of the microchip. (C) Image of a fabricated microfiltration device. Scale bar, 1 mm. (D) Image of the microchip with a reservoir assembled. (E) Brightfield image of a schistosome egg captured in the microfluidic trap. Scale bar, 100 μm.
Fig 2.
Bright-field images of Schistosoma haematobium eggs.
Scale bars, 500 μm (A) and 100 μm (B).
Fig 3.
Computational fluid dynamics simulation.
(A) Streamline velocity of the fluid flow in the microfiltration device. Color bar represents the fluid velocity. (B) Two-dimensional profiles of streamline velocity before and after trapping an egg. (C) 2D simulation of the sequential loading. After capture of the first egg, the following egg is diverted to the adjacent channel. The color represents the magnitude of velocity. (D) The pressure field in the cross-section in depth 50 μm of the chamber. Color bar represents the pressure. (E) Pressure drop across a trapping channel as a function of the volumetric flow rate.
Fig 4.
Sequential loading of eggs into the microfluidic traps.
(A-D) Time-lapse images of Schistosoma haematobium eggs trapping. The fluid was flowing from left to right. Black arrows indicate trapping of schistosome eggs. The duration of the experiment was 60 sec. Scale bar, 500 μm.
Fig 5.
Schistosome eggs capture and enumeration.
(A) Trapping efficiency of the microfiltration device by withdrawing samples from the outlet or infusing samples through inlet. (B) Trapping efficiency of the device at different flow rates. (C) Calibration of the trapping efficiency by spiking various number of egg into the sample. (D) Capture of schistosome eggs in urine and normal saline.
Fig 6.
Recovery of schistosome eggs from the microfiltration device.
(A) Micrographs of the microfluidic chamber before egg capture. (B) Schistosome eggs were captured in the microfluidic trap. (C) Recovery of schistosome eggs by pipetting the sample out from the inlet. Scale bars, 500 μm.
Fig 7.
On-chip fluorescence characterization of schistosome eggs.
(A) Fluorescence, brightfield and combined images of an egg capture in the microfluidic array. Scale bar: 100 μm. (B-D) Confocal fluorescence characterization of eggs of Schistosoma haematobium. Arrow and stars indicate the neural mass primordium and blastomere pairs. Arrow heads represent the flame cells. The eggs were double-labelled with phalloidin (red) and Sytox Green (green). Scale bars, 50 μm.