Rapid automatic nucleic acid purification system based on gas-liquid immiscible phase.

The continuous expansion of nucleic acid detection applications has resulted in constant developments in rapid, low-consumption, and highly automated nucleic acid extraction methods. Nucleic acid extraction using magnetic beads across an immiscible phase interface offers significant simplification and parallelization potential. The gas-liquid immiscible phase valve eliminates the requirement for complicated cassettes and is suitable for automation applications. By analyzing the process of magnetic beads crossing the gas-liquid interface, we utilized a low magnetic field strength to drive large magnetic bead packages to cross the gas-liquid interface, providing a solution of high magnetic bead recovery rate for solid-phase extraction with a low-surfactant system based on gas-liquid immiscible phase valve. The recovery rate of magnetic beads was further improved to 90%-95% and the carryover of the reagents was below 1%. Consequently, a chip and an automatic system were developed to verify the applicability of this method for nucleic acid extraction. The Hepatitis B virus serum standard was used for the extraction test. The extraction of four samples was performed within 7 minutes, with nucleic acid recovery maintained above 80% and good purity. Thus, through analysis and experiments, a fast, highly automated, and low-consumption nucleic acid recovery method was proposed in this study.

[Investigation of intestinal nematode infections in Hongze County, Jiangsu Province].

OBJECTIVE: To understand the situation of intestinal nematode infections and assess the preventive effects, so as to provide the evidence for formulating the further measures of prevention. METHODS: Five villages from 5 townships of different geographical locations were selected and 500 residents of each village were surveyed. The eggs of intestinal nematodes were detected by the Kato-Katz technique, and 50 students and 50 residents per village were investigated by questionnaires about health education. RESULTS: Among 3 011 people detected, 17 persons were infected with intestinal nematodes and the total infection rate was 0.56%. The rates of Ascaris lumbricoides, hookworm, Trichuris trichiura, Enterobius vermicularis, and Trichostrongylus were 0.10%, 0.33%, 0.03%, 0.03% and 0.07%, respectively. The awareness rate of health knowledge was 97.80% and the formation rate of health behavior was 97.00%. CONCLUSION: The infection rates of intestinal nematodes, the awareness rate of health knowledge and the formation rate of health behavior in the population of Hongze County have achieved the criteria of effective control of intestinal parasitic diseases.