The handling of chemicals in the laboratory presents a challenge in instructing large class sizes and when students are relatively new to the laboratory environment. In this work, we describe and demonstrate an augmented reality colorimetric titration tool that operates out of the smartphone or tablet of students. It allows multiple students to conduct the exercise at the same time, respond quickly to actions made, and correctly depict the colors associated with changes in pH values for the indicator used. The tool imbues unparalleled realism in the conduct of the experiment and offers to strongly help students acquire bench skills with minimal use of liquid chemicals, thereby reducing handing risks for them and resulting in lower negative impacts on the environment. The feedback received from undergraduate students that participated in an initial small test exercise with the tool corroborates this.
Physical properties of primary cilia membranes in living cells were examined using two independent, high-spatiotemporal-resolution approaches: fast tracking of single quantum dot-labeled G protein-coupled receptors and a novel two-photon super-resolution fluorescence recovery after photobleaching of protein ensemble. Both approaches demonstrated the cilium membrane to be partitioned into corralled domains spanning 274 ± 20 nm, within which the receptors are transiently confined for 0.71 ± 0.09 s. The mean membrane diffusion coefficient within the corrals, = 2.9 ± 0.41 µm/s, showed that the ciliary membranes were among the most fluid encountered. At longer times, the apparent membrane diffusion coefficient, = 0.23 ± 0.05 µm/s, showed that corral boundaries impeded receptor diffusion 13-fold. Mathematical simulations predict the probability of G protein-coupled receptors crossing corral boundaries to be 1 in 472. Remarkably, latrunculin A, cytochalasin D, and jasplakinolide treatments altered the corral permeability. Ciliary membranes are thus partitioned into highly fluid membrane nanodomains that are delimited by filamentous actin.
Quantitative microscopy shows that protein-sorting signals have opposite effects on ciliary enrichment of G protein–coupled receptors in different cell types, revealing distinct ciliary trafficking mechanisms among ciliated cells.
Microplates with deep hydrophobic coated wells are standard tools in analytical research and clinical diagnostic screening. High throughput screening demands the dispensation of small volumes of liquid; which, in turn, exacts precise positioning in instrumentation. This precision condition can be significantly relaxed in the approach described here where droplets are released at the entrance of the well and fill it by capillary forces alone; provided that a critical diameter to volume condition dependent on the liquid-solid hydophibicity is fulfilled. After filling, the liquid column typically remains stationary even if the bottom end of the well is open.
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