Background Tissue-on-a-chip systems have been a promising means of mimicking and understanding the complex and convoluted functions of the in vivo blood-brain barrier (BBB). These semipermeable borders of endothelial cells are highly selective in order to protect the fragile central nervous system (CNS) from bloodborne pathogens or inflammatory signals and are known to have a…
Background From previous experimental results as well as COMSOL simulations presented in our older posts, we observed a universal non-uniform analyte distribution in the μSIM bottom channel due to limited lateral diffusion rate. This uneven distribution profile will limit our sensitivity in using small volumes of supernatants collected from the ports which are far away…
Background We at Michigan have been aiming to perform sequential small volume sampling coupled with our ultrasensitive digital immunoassay to provide longitudinal data from the uSIM. We have encountered repeatability problems as well as low molecule abundancy with shortly incubated samples collected from the bottom microfluidic channel. Therefore, COMSOL simulation work has been done to…
Background Previously, we have demonstrated multiplexed digital sensing on MCP1, KC and TNFα secreted by RAW 264.7 cells stimulated in conventional cell culturing well plates. We observed decent TNFα and strong MCP1 response but no KC secretion from RAW cells upon 100ng/ml of LPS stimulation overnight. The work verified our platform’s capability of multiplex cytokine…
Mouse CCL2/MCP1 and CXCL1/KC pre-equilibrium digital ELISA has been developed with the current dynamic range set to be 4-500pg/ml for CCL2/MCP1 and 8-1000pg/ml for CXCL1/KC. This initial dynamic range was selected by inferring from the ELISA kit reagent working concentration given by the vendor R&D systems (1.9-250pg/ml for CCL2/MCP1 & 8-1000pg/ml for CXCL1/KC) and can…
IntroductionThe ability to continuously sample and assay for the levels of soluble factors without disrupting the microenvironment is important to acquire sequential secretion profiles in BBB experiments on an uSIM module. Combining small volume sampling, buffer replenishment and sensitive pedELISA technology would enable longitudinal assays of proteins introduced to blood compartment or released from cells….