Shrinking screening for drugs
Scientists in the US have found a way to screen for potential drugs using just minuscule amounts of chemical reagents.
Brian Cunningham and Charles Choi at the University of Illinois at Urbana-Champaign have designed a 96-well microplate that reduces the volume of precious chemicals needed to perform a drug screening assay.
This is no run of the mill microplate. Turn it over and you will see that its bottom surface is actually an elaborate network of fluid channels integrated with biosensors.
Microplates, flat plates with multiple wells used as tiny test tubes, are used in high-throughput screening (HTS). In HTS scientists screen though thousands of chemical compounds looking for an interaction with a target protein, which is a critical part of a disease process.
Detection of these biochemical interactions without the use of fluorescent labels is desirable as it can be tricky to add these labels in a reproducible way, and sometimes just impossible at all. Optical biosensors, like the photonic crystal ones used in this microplate, detect these interactions through the change in dielectric permittivity that occurs on the surface of the biosensor when molecules attach to it.Integrating biosensors with microfluidic channels allows the scientist to reduce the quantity of chemicals they use. However, not many biosensors are capable of interfacing with a large number of microfluidic channels in parallel, especially when the biosensors and fluid channels are small, said Cunningham.
In each 12-well row within the microplate, the fluid channels form 11 analyte wells. They are gathered to a single detection region, where all 11 channels can be monitored at once. A central common well in each row serves as an access point for introduction or withdraw of reagents for the flow channels.
They plan, said Cunningham, is to increase the level of integration so that a single three by five inch photonic crystal surface can support around 2500 microfluidic channels and assays.
Sarah Corcoran
A 96-well microplate incorporating a replica molded microfluidic network integrated with photonic crystal biosensors for high throughput kinetic biomolecular interaction analysis
Charles J. Choi and Brian T. Cunningham, Lab Chip, 2007
DOI: 10.1039/b618584c
Source: Royal Society of Chemistry
