Detection of influenza virus using a lateral flow immunoassay for amplified DNA by a microfluidic RT-PCR chip.

Influenza virus RNA was amplified by a continuous-flow polydimethylsiloxane microfluidic RT-PCR chip within 15-20 min. The amplified influenza virus RNA was observed with the naked eye, as the red color at the test line, using a lateral flow immunoassay within 1 min.

Semi-real time electrochemical monitoring for influenza virus RNA by reverse transcription loop-mediated isothermal amplification using a USB powered portable potentiostat.

In this paper, the semi-real time electrochemical monitoring method using a screen-printed electrode, which employs reverse transcription loop-mediated isothermal amplification (RT-LAMP) for influenza virus RNA, is presented. The amplified DNA combined with methylene blue (MB), which was used as an electroactive DNA intercalator, and the electrochemical signal was monitored using square wave voltammetry in the presence of RT-LAMP reagent components. MB molecules binding to amplified DNA caused the reduction of the peak current due to the slow diffusion of MB-amplified DNA complex to the electrode surface. We successfully monitored the amplification process of DNA on the basis of RT-LAMP by measuring and analyzing the electrochemical signal of MB with only one screen-printed electrode that connected with a USB powered portable potentiostat. The peak height of the current was related to the extent of amplification of DNA and the amount of input RNA. Since laborious probe immobilization is not required and both the amplification and the monitoring are possible in a single tube, our method does not suffer from potential cross-contamination. Furthermore, our method provides a new rote for the development of electrochemical hand held biosensors.

Immunochromatographic assay using gold nanoparticles for measuring salivary secretory IgA in dogs as a stress marker.

The concentration of salivary secretory immunoglobulin A (sIgA) is a well-known stress marker for humans. The concentration of salivary sIgA in dogs has also been reported as a useful stress marker. In addition, salivary sIgA in dogs has been used to determine the adaptive ability of dogs for further training. There are conventional procedures based on enzyme-linked immunosorbent assay (ELISA) for measuring salivary sIgA in dogs. However, ELISA requires long assay time, complicated operations and is costly. In the present study, we developed an immunochromatographic assay for measuring salivary sIgA in dogs using a dilution buffer containing a non-ionic surfactant. We determined 2500-fold dilution as the optimum condition for dog saliva using a phosphate buffer (50 mM, pH 7.2) containing non-ionic surfactant (3 wt% Tween 20). The results obtained from the saliva samples of three dogs using immunochromatographic assay were compared with those obtained from ELISA. It was found that the immunochromatographic assay is applicable to judge the change in salivary sIgA in each dog. The immunochromatographic assay for salivary sIgA in dogs is a promising tool, which should soon become commercially available for predicting a dog's psychological condition and estimating adaptive ability for training as guide or police dogs.

Stability of cellular foam generated from amphoteric surfactant aqueous solution.

Experiments were carried out to investigate the stability of cellular foam generated from an amphoteric surfactant aqueous solution in a standard bubble column. A typical growth and collapse process were found, and the cellular foam became stable with increasing pH of the solution under both acidic and basic conditions. The critical film thickness calculated from the thinning equation, the well-known Reynolds equation, was between 100 to 400 nm. Of particular note is that the cellular foam was not observed at pH=7 of the liquid.

Production of sepedonin by Sepedonium chrysospermum NT-1 in submerged culture.

Strains of Sepedonium chrysospermum and the anamorph strain of Hypomyces chrysospermus (congruent with Apiocrea chrysosperma) were isolated and purified from parasitic filamentous fungi on the fruiting bodies of Boletaceae, such as the Gyroponus and Suillus genera in Japan, and identified from formations of conidia and chlamydospores. It is known that these strains produce sepedonin. S. chrysospermum NT-1 strain was selected from these strains and isolated. As the optimum medium (CY-1 medium), 0.1% yeast extract was added to the fruiting-body-forming medium (C medium) of Schizophyllum commune. After 8 days of growth on CY-1 medium, the yield of sepedonin was about 34 mg per 2 g of glucose added. This sepedonin seemed to inhibit the growth of various gram-positive and gram-negative bacteria, yeasts and molds.