Lijun Yang

β-Actin is a useful internal control for tissue-specific gene expression studies using quantitative real-time PCR in the half-smooth tongue sole Cynoglossus semilaevis challenged with LPS or Vibrio anguillarum.

beta-Actin has been frequently used as an internal control (gene) or as a housekeeping gene to normalize the expression of the target gene(s) or mRNA levels between different samples. However, the beta-actin expression has been shown to be influenced by the sample type and experimental conditions. If beta-actin could be used as a reference gene for the half-smooth tongue sole Cynoglossus semilaevis remains ill-defined. Here we evaluate the tissue-specific beta-actin gene expression pattern in C. semilaevis when challenged with antigenic agents namely, lipopolysaccharide (LPS) or Vibrio anguillarum employing absolute quantitative real-time PCR. The real-time PCR was performed based on the standard curve generated from recombinant plasmids. No significant differences in beta-actin expression were found between treated and untreated tissue samples. We thus conclude that beta-actin could be used as a reliable internal reference gene for real-time PCR based quantitation of gene expression studies in various tissue samples of C. semilaevis challenged with LPS or pathogenic bacteria.

Simultaneous determination of 7 arsenic species in chicken muscle and chicken liver with high performance liquid chromatography-inductively coupled plasma mass spectrometry: Simultaneous determination of 7 arsenic species in chicken muscle and chicken liver with high performance liquid chromatography-inductively coupled plasma mass spectrometry

A method for the simultaneous determination of 7 arsenic species was developed with high performance liquid chromatography and inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The sample was extracted with artificial gastric juice. The HPLC separation was performed on an anion analytical column utilizing a gradient elution program of ammonium carbonate and water as the mobile phase. Identification and quantification were achieved by ICP-MS. Good linearities of 7 arsenic species were observed in the range from 1 microg/kg to 50 microg/kg with the correlation coefficients greater than 0.999. The average recoveries of 7 arsenic species spiked at the three levels of 1, 2 and 10 microg/kg ranged from 84.3% to 106.6% with the relative standard deviations of 1.4%-4.2%. The quantification limits of 7 arsenic species were 1 microg/kg. The method was proved to be good reproducibility, high sensitivity and simple preprocessing. This method is suitable for the simultaneous determination of 7 arsenic species in chicken muscle and chicken liver.