Experimental validation of numerical study on thermoelectric-based heating in an integrated centrifugal microfluidic platform for polymerase chain reaction amplification.

A comprehensive study involving numerical analysis and experimental validation of temperature transients within a microchamber was performed for thermocycling operation in an integrated centrifugal microfluidic platform for polymerase chain reaction (PCR) amplification. Controlled heating and cooling of biological samples are essential processes in many sample preparation and detection steps for micro-total analysis systems. Specifically, the PCR process relies on highly controllable and uniform heating of nucleic acid samples for successful and efficient amplification.

Flow-enhanced electrochemical immunosensors on centrifugal microfluidic platforms.

We present a novel fully integrated centrifugal microfluidic device with features for target antigen capture from biological samples, via a bead-based enzyme-linked immune-sorbent assay, and flow-enhanced electrochemical detection. The limit of detection (LOD) of our device for the C-reactive protein (CRP) was determined to be 4.9 pg mL(-1), a 17-fold improvement over quantification by optical density.

Serum complement enhances the responses of genotoxin- and oxidative stress-sensitive Escherichia coli bioreporters.

Bacterial bioreporters are limited in their abilities to detect large polar molecules due to their membrane selectivity. In this study, the activity of serum complement was used to bypass this undesired selectivity. Initially, the serum complement activity was assessed using the responses of a bacterial bioreporter harboring a recA::luxCDABE transcriptional fusion when exposed to the chemotherapy drug, mitomycin C (MMC).

Lab-on-DVD: standard DVD drives as a novel laser scanning microscope for image based point of care diagnostics.

We present a novel "Lab-on-DVD" system and demonstrate its capability for rapid and low-cost HIV diagnostics by counting CD4+ cells isolated from whole blood. We show that a commercial DVD drive can, with certain modifications, be turned into an improved DVD-based laser scanning microscope (DVD-LSM). The system consists of a multi-layered disposable polymer disc and a modified commercial DVD reader with rotational control for sample handling, temperature control for optimized bioassay, a photodiode array for detection, and software for signal processing and user interface - all the necessary components required for a truly integrated lab-on-a-chip system, with the capability to deliver high-resolution images down to 1 μm in size.

Large-volume centrifugal microfluidic device for blood plasma separation.

Background: Microfluidic-based systems are ideal for handling small microliter volumes of samples and reagents, but 'real-world' or clinical samples for bioanalysis are often on the milliliter scale. We aimed to develop and validate a large-volume centrifugal or compact disc-based device for blood plasma separation, capable of processing 2 ml undiluted blood samples.

Results: This automated blood sample preparation device was shown to yield high purity plasma in less than half the time of commercial plasma preparation tubes, while enabling integration with downstream analysis and detection steps.

Centrifugal microfluidics for biomedical applications.

The centrifugal microfluidic platform has been a focus of academic and industrial research efforts for almost 40 years. Primarily targeting biomedical applications, a range of assays have been adapted on the system; however, the platform has found limited commercial success as a research or clinical tool. Nonetheless, new developments in centrifugal microfluidic technologies have the potential to establish wide-spread utilization of the platform.

Numerical modeling and experimental validation of uniform microchamber filling in centrifugal microfluidics.

In this paper, a comprehensive approach to numerical and experimental analysis of microchamber filling in centrifugal microfluidics is presented. In the development of micro total analysis systems, it is often necessary to achieve complete, uniform filling of relatively large microchambers, such as those needed for nucleic acid amplification or detection. With centrifugal devices, these large microchambers must often be orientated perpendicularly to the direction of centrifugal force and are usually bounded by materials with varying surface properties.