Agilent VEE Pro is an interactive graphical programming environment for test automation, measurements and advanced analysis. It includes numerous graphical objects suitable for small or large programs and a range of testing applications. VEE Pro also provides direct access to LXI instruments through their built-in Web interface (Figure 1).

With built-in tools for data analysis and visualization, VEE Pro also makes it possible to transform basic measurements of, for example, voltage and current into derived measurements of bioanalytical characteristics. This enables applications in fields such as disease diagnosis, biohazard detection, chemical detection, and safety testing of foods and pharmaceuticals.

Measurement devices such as the LXI Class C-compliant Agilent 34410A and 34411A digital multimeters (DMMs) provide the voltage and current measurements necessary for applications in bioanalysis, biomedical device development and more. For example, the development of electrochemical-based biosensors requires intensive characterization of conductimetric, amperometric, potentiometric and impedimetric measurements. The required measurements of conduction, resistance, electrical fields and enzymes are performed through characterization of electric current and oxidation reaction to voltage.

Another example is the analysis of hazardous or contagious substances, which pose safety risks to research staff. In such cases, measurements can be performed remotely using LXI instruments, avoiding health risks and aiding compliance with safety regulations. The ability to perform monitoring, control and analysis remotely can also be used as a tool for remote learning in universities and research institutes (Figure 2).

Figure 2. LXI-based instrumentation lends itself to a variety of useful applications in life sciences and chemical analysis. Click here to enlarge.

Some experiments require a long time for completion—perhaps overnight or over the weekend. LXI makes monitoring experiments away from the lab possible. With proper Internet access, and depending on an organization’s security policies, an experiment can be monitored and controlled from virtually anywhere in the world. While connected to an experiment, researchers may also be able to access database servers if they require additional analysis of the measured data.

As a final example, results can be produced in real time for techniques such as the qualitative analytical methods used for substance identification through a database of substance matrices. The measured data can also be used for cross-validation between laboratories to check the quality of bioanalytical data.

Sketching example systems

Looking more closely at bioanalytical measurements, LXI instruments can be used in developing microfluidics or “lab-on-a-chip” (LOC) systems. These comprise devices that perform laboratory functions on a small scale by integrating miniaturized tubing, valves, mixers, biosensors, detectors and more. These devices are used mainly for detecting biochemical substances such as proteins, nucleic acids and biological cells.

LOC systems require fundamental measurements of the electrical characteristics of liquid, thermal and electrokinetics transport systems. Agilent LXI-compliant instruments provide a basic analytical solution for such measurements in a single platform (Figure 3).

Figure 3. A variety of LXI-compliant instruments provide essential measurements applicable to LOC-based systems. Click here to enlarge.

The LOC method called DNA amplification is performed through a polymerase chain reaction (PCR) technique that is fabricated using micro-electromechanical systems (MEMS). The efficiency of PCR analysis depends on the accuracy of temperature and thermal-cycle controls. These can be easily implemented with the Agilent N6705A power analyzer and the 34980A multifunction switch/control unit while monitoring biochemical reactions. Both of N6705A and 34980A are LXI Class C compliant.

Another important LOC method is diaelectrophoresis (DEP). It enables cell separation and manipulation by applying an electric field induced in biological cells. The LXI Class C-compliant Agilent 33220A function generator can be programmed to provide signals at the required frequencies and amplitude levels to excite cells between microchannel electrodes. In DEP, the determination of particle size is a function of the excitation frequency. This is, of course, an impedance measurement that can be performed by the Agilent E4980A LCR meter, which measures conductivity and electrode capacitance; particle size can be derived from these parameters.

Conclusion

LXI-based instrumentation is a powerful and promising choice for challenging measurement applications in the life sciences and chemical analysis. LXI simplifies test processes through a versatile instrument-control platform that includes remote monitoring and control of experiments.

For more information, contact Nilavarasan Periasamy, Test System Development Expert with Agilent Technologies, at periasamy_nilavarasan@agilent.com or visit www.agilent.com.