Single-tube-genotyping of gastric cancer related SNPs by directly using whole blood and paper-dried blood as starting materials

Relationship between EGF, TGFA, and EGFR Gene Polymorphisms and Traditional Chinese Medicine ZHENG in Gastric Cancer

In traditional Chinese medicine (TCM), correct syndrome differentiation is the most important principle guiding the prescription of Chinese herbal formulae for the treatment of gastric cancer (GC). We aimed to reveal the genetic mechanisms underlying GC syndrome differentiation (ZHENG) in a population of 387 GC patients. Twenty-nine single nucleotide polymorphisms (SNPs) in EGF, TGFA, and EGFR were investigated. Two SNPs, rs11466285 in TGFA and rs884225 in EGFR, were significantly associated with the distribution of ZHENG (P < 0.05). The rs11466285 TT genotype increased the risk of damp heat with toxin (DHT) and deficiency of both Qi and yin (DQY) compared with obstruction of blood stasis (OBS). The rs884225 AA genotype could increase the risk of DQY and deficiency of both Qi and blood (DQB) compared with yin deficiency due to stomach heat (YDSH). Parallel comparison among the SNPs and syndrome types revealed that DQB was distinct from YDSH, disharmony between the liver and stomach, stagnation of phlegm muddiness (SPM), OBS, and other syndromes at several SNP loci (P < 0.05). The rs11466285 TT and rs884225 AA genotypes exhibit increased risk of DQB compared with OBS and SPM (P < 0.05), respectively. In conclusion, the formation of GC ZHENG was related to EGF, TGFA, and EGFR gene polymorphisms.

A chip-based immunoaffinity capillary electrophoresis assay for assessing hormones in human biological fluids

A chip-based capillary electrophoresis system has been designed for assessing the concentrations of four hormones in whole human blood, saliva, and urine. The desired analytes were isolated by immunoextraction using a panel of four analyte-specific antibodies immobilized onto a glass fiber insert within the injection port of the chip. Following extraction, the captured analytes were labeled prior to electro-elution into the chip separation channel, where they were resolved into four individual peaks in circa 2 min. Quantification of each peak was achieved by on-line LIF detection and integration of the area under each peak. Comparison to commercial high-sensitivity immunoassays demonstrated that the chip-based assay provided fast, accurate, and precise measurements for the analytes under investigation. As the availability of commercially available antibodies rapidly expands, the application of this system will greatly increase. Chip-based CE separations of multiple analytes from a single sample also provide a significant advantage in the analysis of small samples.

Elimination of False-Positive Polymerase Chain Reaction Results Resulting from Hole Punch Carryover Contamination

The collection of biological material (e.g., blood) directly onto filter paper for subsequent use in laboratory assays such as polymerase chain reaction (PCR), has become a common practice. Dried cells or fluid on the paper can be readily rehydrated and retrieved into a standard volume of an appropriate elution buffer but introduces a dilution factor to the sample. The use of a common cutting instrument for excising a standard-sized piece of paper that contains the material also introduces the potential for transferring biological material from one sample to subsequent samples, causing false-positive results by PCR. In the present study, filter-paper-collected blood that contained beak and feather disease virus was used to determine if viral DNA could be transferred between samples by a hole punch used to excise sequential filter papers. It was determined that false-positive results could be obtained at least 13 times after a positive sample. Subsequently, the efficacy of 4 methods of hole punch disinfection, flaming, VirkonS, bleach, and a bleach-ethanol combination, was assessed. The only effective and practical method to destroy DNA was a method where the hole punch was agitated in commercial bleach, rinsed in water, the water was displaced with 100% ethanol and air-dried. This method was simple, cheap, and relatively rapid, and allowed for the use of a single hole punch for a series of samples, without carryover contamination and consequent false-positive results.

High resolution DNA separations using microchip electrophoresis

Planar microfluidic devices have emerged as effective tools for the electrophoretic separation of a variety of different DNA inputs. The advancement of this miniaturized platform was inspired initially by demands placed on electrophoretic performance metrics by the human genome project and has provided a viable alternative to slab gel and even capillary formats due to its ability to offer high resolution separations of nucleic acid materials in a fraction of the time associated with its predecessors, consumption of substantially less sample and reagents while maintaining the ability to perform many separations in parallel for realizing ultra-high throughputs. Another compelling advantage of this separation platform is that it offers the potential for integrating front-end sample preprocessing steps onto the separation device eliminating the need for manual sample handling. This review aims to compile a recent survey of various electrophoretic separations using either glass or polymer-based microchips in the areas of genotyping and DNA sequencing as well as those involving the growing field of DNA-based forensics.