Lab on a Chip Blog

Cells in the microfluidic channels interfere with the laser beam in a standard CD drive and cause errors in reading and decoding the digital data previously burned on the CD

A digital compact disc integrated with a microfluidic device to analyse cells has been developed by scientists in the US. The disc can be inserted into a standard computer disc drive for analysis and could be used to diagnose diseases.

Gang Logan Liu and coworkers at the University of Illinois at Urbana-Champaign built a layer onto a CD that converts biological information into digital information to detect the presence of cells and their size and number. Blood cell counting and sizing are often standard medical practices in the diagnosis of diseases such as leukemia, anemia and Aids.

The team made the device by burning an audio file consisting of a repeating sequence of binary numbers onto a CD’s surface. On top of this, they added a microfluidic layer with a channel. They injected small fluid samples of cells into the channel and focused the laser beam from a CD drive onto the disc’s data layer, which reads the binary code. Any particles on the layer interfere with the laser beam, interrupting the code and altering the data readout in graphs of error against time. The size of the response correlates with the cells’ shape, concentration and optical density.

Read the full Chemistry World article online here or go straight to the Lab on a Chip paper:

Microparticle and cell counting with digital microfluidic compact disc using standard CD drive
Syed M. Imaad, Nathan Lord, Gulsim Kulsharova and Gang Logan Liu
Lab Chip, 2011, Advance Article
DOI: 10.1039/c0lc00451k

The ring structure of the neuron networks was prepared by stamping proteins onto a glass substrate and growing neurons on the proteins

US scientists have created a model of the ring-shaped networks of neurons in the brain, which could help researchers to understand small changes within diseased brain cells.

Henry Zeringue, and colleagues at the University of Pittsburgh, developed the model to enable the study of brain circuitry in an in vitro system instead of using brain slices. In neurological diseases, such as Alzheimer’s disease, subtle changes in this activity take years, or even decades, to become clinically detectable. Most studies only explore the electrical properties of a single neuron or the connection between two neurons. Until now, there hasn’t been a good model to study network activity in vitro.

Zeringue and his team are considering  using their platform to characterise network-level changes based on small experimental perturbations, like changes in network geometry or expression of mutant proteins in 10 per cent of the neurons. ‘Deciphering the relationship between the connectivity of the neurons and the activity in the ring culture will be challenging and unravelling the connections between the neurons may still prove to be a daunting task,’ he concludes.

Read Carl Saxton’s Chemistry World article online here or go straight to the Lab on a Chip paper:

Ring-shaped neuronal networks: a platform to study persistent activity
Ashwin Vishwanathan, Guo-Qiang Bi and Henry C. Zeringue,
Lab Chip, 2011, 11, 1081
DOI: 10.1039/c0lc00450b

The chip consists of a printed integrated circuit and a microfluidic device, powered wirelessly by a palm sized RFID reader

A team of US scientists has developed the first lab on a chip device to be powered remotely.

Wen Qiao at the University of California, San Diego, made a microfluidic chip that can be powered with a commercially available radio frequency transmitter for electrophoresis experiments.

Qiao’s team made the chip by printing a circuit onto a plastic sheet. Within the circuit, they placed a chamber containing microwells.

The device is cheap to produce and simple to use and can be used in the same way as a microscope slide, with the RFID transmitter mounted next to a microscope stage and a camera to capture images of the moving nanoparticles. Qiao says that the chip will ‘greatly simplify the operation of the device for pathologists and clinicians whose training and practices have been mostly on optical microscopes, with limited experience with sophisticated electronic instruments.’

Check out the full Chemistry World story online here or read the Lab on a Chip article:

Wirelessly powered microfluidic dielectrophoresis devices using printable RF circuits
Wen Qiao, Gyoujin Cho and Yu-Hwa Lo
Lab Chip, 2011, Advance Article
DOI: 10.1039/c0lc00457j