This paper presents an integrated microfluidic device on a compact disk (CD) that performs an enzyme-linked immunosorbent assay (ELISA) for rat IgG from a hybridoma cell culture. Centrifugal and capillary forces were used to control the flow sequence of different solutions involved in the ELISA process. The microfluidic device was fabricated on a plastic CD. Each step of the ELISA process was carried out automatically by controlling the rotation speed of the CD. The work on analysis of rat IgG from hybridoma culture showed that the microchip-based ELISA has the same detection range as the conventional method on the 96-well microtiter plate but has advantages such as less reagent consumption and shorter assay time over the conventional method.
A novel extractive fermentation for butyric acid production from glucose, using immobilized cells of Clostridium tyrobutyricum in a fibrous bed bioreactor, was developed by using 10% (v/v) Alamine 336 in oleyl alcohol as the extractant contained in a hollow-fiber membrane extractor for selective removal of butyric acid from the fermentation broth. The extractant was simultaneously regenerated by stripping with NaOH in a second membrane extractor. The fermentation pH was self-regulated by a balance between acid production and removal by extraction, and was kept at approximately pH 5.5 throughout the study. Compared with conventional fermentation, extractive fermentation resulted in a much higher product concentration (>300 g/L) and product purity (91%). It also resulted in higher reactor productivity (7.37 g/L. h) and butyric acid yield (0.45 g/g). Without on-line extraction to remove the acid products, at the optimal pH of 6.0, the final butyric acid concentration was only approximately 43.4 g/L, butyric acid yield was 0.423 g/g, and reactor productivity was 6.77 g/L. h. These values were much lower at pH 5.5: 20.4 g/L, 0.38 g/g, and 5.11 g/L. h, respectively. The improved performance for extractive fermentation can be attributed to the reduced product inhibition by selective removal of butyric acid from the fermentation broth. The solvent was found to be toxic to free cells in suspension, but not harmful to cells immobilized in the fibrous bed. The process was stable and provided consistent long-term performance for the entire 2-week period of study.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.