Mapping the Pharyngeal and Intestinal pH of Caenorhabditis elegans and Real-Time Luminal pH Oscillations Using Extended Dynamic Range pH-Sensitive Nanosensors

• DOI: 10.1021/nn401856u
• Publication Date: 2013-05-14T01:39:57Z
• Authors: Veeren M. Chauhan; Gianni Orsi; Alan Brown; David I. Pritchard; Jonathan W. Aylott
• Keywords: Nanosensor; Lumen (anatomy)

Extended dynamic range pH-sensitive ratiometric nanosensors, capable of accurately mapping the full physiological pH range, have been developed and used to characterize pharyngeal intestinal lumen Caenorhabditis elegans in real-time. Nanosensors, 40 nm diameter, were prepared by conjugating fluorophores, carboxyfluorescein (FAM) Oregon Green (OG) a 1:1 ratio, reference fluorophore, 5-(and-6)-carboxytetramethylrhodamine (TAMRA) an inert polyacrylamide matrix. Accurate measurements calculated through determination fluorescence ratio between fluorophores. Nanosensors calibrated with automated image analysis system validated demonstrate measurement resolution ±0.17 units. The motility C. populations, as indicator for viability, showed nematodes treated concentrations ranging from 50.00 3.13 mg/mL, not statistically different challenged nanosensors up period 4 days (p < 0.05). also found remain >24 h after nanosensor challenge was removed. viable 5.96 ± 0.31 anterior pharynx 3.59 0.09 posterior intestine. pumping rate, which dictates transfer ingested material intestine, be temperature dependent. Imaging at °C reduced rate 7 contractions/min enabled reconstruction rhythmic oscillations real-time microscopy.