Use of the µSiM in a diagnostics application
Introduction We are interested in exploring whether certain types of extracellular vesicles (EVs) may be more likely to become trapped while crossing the blood-brain barrier (BBB). Specifically, we are curious if EVs possessing certain types of surface integrins might bind to the vascular basement membrane that surrounds the exterior of brain blood vessels to become…
Introduction As what we’ve learned from the previous “Catch-and-Display Immunoassay” (CAD-IA) trials, we switched to an antibody pair from OriGene with low non-specific binding ability to each other and start to conduct ultracentrifugation for all reactive reagents for the reduction of protein aggregations. However, we found an inconsistency of co-localization percentage of immunocomplexes and beads…
Introduction This post will describe the preliminary work I have completed using size exclusion chromatography (SEC) for EV enrichment. We are ultimately interested in interrogating serum EV biomarkers using CAD-LB, however, the presence of protein and lipoprotein contaminants reduces the capacity for EV capture (~104) on NPN membranes and may hinder the analysis of rare…
Introduction This post provides an update on a series of experiments conducted with Sam. These experiments were designed to assess the versatility of the CAD-LB platform for detecting EVs in urine samples. Urine is a complex biofluid often used in clinical diagnosis, making it a suitable subject for testing the CAD-LB’s biomarker detection capabilities. After…
Introduction This post is another update in my series of experiments aiming to both characterize and validate the CAD-LB platform. We have now shifted our focus to validating CAD-LB biomarker detection which will be done using multiple experimental models. The most recent model, and the topic of this post, uses HUVEC cells to validate the…
Introduction In this post I will review work I have completed to further characterize the CAD-LB platform. In this set of experiments combinations of nanoparticle species were used to define colocalization limitations. More specifically, two nanoparticle species each labeled with a unique fluorescent dye (red or blue) were used to simulate pan EV and antibody…
Introduction This post is meant to serve as an update for some of the more recent work completed on the CAD-LB (catch and display for liquid biopsy) platform. The CAD-LB is intended to be used as a digital biomarker assay for interrogating small extracellular vesicles (sEVs). Since transitioning our assay to the µSIM device we…
The development of the μSiM-DX has been swift and focused, as discussed in these previous blog posts: https://trace-bmps.org/beadazzled-laying-the-foundation-of-the-%ce%bcsim-dx-fouling-based-sensor/ and https://trace-bmps.org/vindictive-virus-capture-testing-the-%ce%bcsim-dx-with-vaccinia-virus-towards-a-modular-virus-diagnostic/. To provide a greater understanding of the inner workings of the device, I have done a few calculations regarding some of its working properties related to microfluidics. The three I present here are about the relationship…
After completing proof of concept testing with polystyrene beads and with the goal of creating a SARS-CoV-2 sensor (Discussed in this post: https://trace-bmps.org/beadazzled-laying-the-foundation-of-the-%ce%bcsim-dx-fouling-based-sensor/), we sought to test the performance of the system with a target more similar to the SARS-CoV-2 virus. We found this target in vaccinia virus. As we did with the polystyrene beads,…
Starting in December of 2019, we began capturing fluorescent beads on microslit silicon nanomembranes as an illustrative representation of particle capture within our microfluidic devices. From then until now we have successfully used this method within gasket made TFAC devices and uSiM ALine devices using a range of micropore sizes/shapes and bead sizes. These experiments…