Portable capillary electrophoresis system for identification of cattle breeds based on DNA mobility

Low-cost automated capillary electrophoresis instrument assembled from commercially available parts

A CE instrument that can be assembled from commercially available components with minimal construction effort is described. Except for the electronic control circuitry no specially made parts are required. It is based on a flexible design of microfluidic, electropneumatic, and electronic sections and different configurations can easily be implemented. Automated injection into the capillary is performed hydrodynamically by the application of a pressure for a controlled length of time. The performance of the device was tested with a contactless conductivity detector by separating different metal ions. In addition, nine metal cations related to the quality of honey were separated in 2.3 min and four honey samples were analysed quantitatively to demonstrate the applicability of the method.

Voltage-programming-based capillary gel electrophoresis for the fast detection of angiotensin-converting enzyme insertion/deletion polymorphism with high sensitivity

A voltage-programming-based capillary gel electrophoresis method with a laser-induced fluorescence detector was developed for the fast and highly sensitive detection of DNA molecules related to angiotensin-converting enzyme insertion/deletion polymorphism, which has been reported to influence predisposition to various diseases such as cardiovascular disease, high blood pressure, myocardial infarction, and Alzheimer's disease. Various voltage programs were investigated for fast detection of specific DNA molecules of angiotensin-converting enzyme insertion/deletion polymorphism as a function of migration time and separation efficiency to establish the effect of voltage strength to resolution. Finally, the amplified products of the angiotensin-converting enzyme insertion/deletion polymorphism (190 and 490 bp DNA) were analyzed in 3.2 min without losing resolution under optimum voltage programming conditions, which were at least 75 times faster than conventional slab gel electrophoresis. In addition, the capillary gel electrophoresis method also successfully applied to the analysis of real human blood samples, although no polymorphism genes were detected by slab gel electrophoresis. Consequently, the developed voltage-programming capillary gel electrophoresis method with laser-induced fluorescence detection is an effective, rapid analysis technique for highly sensitive detection of disease-related specific DNA molecules.

Portable capillary electrophoresis instrument with contactless conductivity detection for on-site analysis of small volumes of biological fluids

A novel, easy to use and portable capillary electrophoretic instrument for injection of small volumes of biological fluids equipped with contactless conductivity detection was constructed. The instrument is lightweight (<5 kg), all necessary parts including a tablet computer are accommodated in a plastic briefcase with dimensions 20 cm × 33 cm × 17 cm (w × l × h), allows hydrodynamic injection of small sample volumes and can continuously operate for at least 10 hours. The semi-automated hydrodynamic sample injection is accomplished via a specially designed PMMA interface that is able to repeatedly inject sample aliquots from a sample volume as low as 10 μL, with repeatability of peak areas below 5%. The developed interface and the instrument were optimized for the injection of biological fluids. Practical utility was demonstrated on the determination of formate in blood serum samples from acute methanol intoxication patients and on the analysis of ionic profile (nitrosative stress markers, including nitrite and nitrate) in the exhaled breath condensate from one single exhalation.

Fast on-site diagnosis of influenza A virus by Palm PCR and portable capillary electrophoresis

A method combining Palm polymerase chain reaction (PCR) and portable capillary electrophoresis (CE) was developed for rapid on-site analysis of influenza A (H1N1) virus. The portable CE system was suitable for rapid diagnosis which was able to detect a sample in ∼4 min after sample loading, while the 'Palm PCR' system allowed for high-speed nucleic acid amplification in ∼16 min. The analysis time from DNA sample to analysis of amplified target DNA molecule was only ∼20 min, which was significantly less than slab gel electrophoresis with other commercially available PCR machine. When the 100-bp DNA ladder was separated, the relative standard deviation values (n=5) for the migration times and peak areas of the 100 and 200-bp DNA molecules were 0.26 and 8.9%. The detection limits were 6.3 and 7.2 pg/μL, respectively. The combined method was also able to identify two influenza A-associated genes (the HA and NP genes of the novel H1N1 influenza). CE separation was achieved with a sieving matrix of 1% poly(vinylpyrrolidone) (Mr=1,300,000) in 1× TBE buffer (pH 8.45). The combined Palm PCR-portable CE system should provide an improved, fast on-site molecular genetic diagnostic method.

Unmanned platform for long-range remote analysis of volatile compounds in air samples

This paper describes a long-range remotely controlled CE system built on an all-terrain vehicle. A four-stroke engine and a set of 12-V batteries were used to provide power to a series of subsystems that include drivers, communication, computers, and a capillary electrophoresis module. This dedicated instrument allows air sampling using a polypropylene porous tube, coupled to a flow system that transports the sample to the inlet of a fused-silica capillary. A hybrid approach was used for the construction of the analytical subsystem combining a conventional fused-silica capillary (used for separation) and a laser machined microfluidic block, made of PMMA. A solid-state cooling approach was also integrated in the CE module to enable controlling the temperature and therefore increasing the useful range of the robot. Although ultimately intended for detection of chemical warfare agents, the proposed system was used to analyze a series of volatile organic acids. As such, the system allowed the separation and detection of formic, acetic, and propionic acids with signal-to-noise ratios of 414, 150, and 115, respectively, after sampling by only 30 s and performing an electrokinetic injection during 2.0 s at 1.0 kV.

On-line capillary electrophoresis for enhanced detection sensitivity of feline panleukopenia virus

A rapid on-line capillary electrophoresis (CE) method for highly sensitive detection of DNA molecules with specific lengths was developed based on the combination of base stacking (BS) and programmed field strength gradients (PFSG). The BS method has been performed for on-column concentration to improve detection sensitivity without any modification of the CE system. PFSG increased the electrophoretic velocity of DNA molecules, which effectively decreased analysis time. Using the BS and PFSG combination, the amplified PCR product (340-bp DNA) of cats infected with feline panleukopenia virus was detected within 6.5min. Detection sensitivity (∼10-fold) was enhanced compared to conventional CE analysis. The combined on-line CE/BS-PFSG methodology could be an effectively rapid analysis technique for the highly sensitive detection of disease-related specific DNA molecules.