1.Direct detection of circulating free DNA extracted from serum samples of breast cancer using locked nucleic acid molecular beacon.
Gui Z1, Wang Q2, Li J1, Zhu M1, Yu L1, Xun T1, Yan F3, Ju H4. Talanta. 2016 Jul 1;154:520-5. doi: 10.1016/j.talanta.2016.04.008. Epub 2016 Apr 7.
As an emerging noninvasive blood biomarker, circulating free DNA (cfDNA) can be utilized to assess diagnosis, progression and evaluate prognosis of cancer. However, cfDNAs are not "naked", they can be part of complexes, or are bound to the surface of the cells via proteins, which make the detection more challenging. Here, a simple method for the detection of Ubiquitin-like with PHD and ring finger domains 1 (UHRF1) DNA exacted from serum of breast cancer (BC) has been developed using a novel locked nucleic acid molecular beacon (LNA-MB). In order to enhance the stability and detection efficiency of the probe in biofluids, we design a shared-stem molecular beacon containing a 27-mer loop and a 4-mer stem with DNA/LNA alternating bases. The fluorescence is released in the presence of target. The detection procedure is simple and can be completed within 1h. This method shows a sensitive response to UHRF1 DNA with a dynamic range of 3 orders of magnitude.
2.Temperature-Mediated Variations in Cellular Membrane Fatty Acid Composition of Staphylococcus aureus in Resistance to Pulsed Electric Fields.
Wang LH1, Wang MS1, Zeng XA2, Liu ZW1. Biochim Biophys Acta. 2016 May 4. pii: S0005-2736(16)30145-6. doi: 10.1016/j.bbamem.2016.05.003. [Epub ahead of print]
Effects of growth temperature on cell membrane fatty acid composition, fluidity and lethal and sublethal injury by pulsed electric fields (PEF) in Staphylococcus aureus ATCC 43300 (S. aureus) in the stationary phase were investigated. Analysis of the membrane fatty acids by gas chromatography-mass spectrometry (GC-MS) revealed that branched chain fatty acids (iso C14:0, iso C15:0, anteiso C15:0 and anteiso C17:0) and straight chain fatty acids (C12:0, C14:0, C16:0, C17:0 and C18:0) were primary constituents in the membrane. The S. aureus changed its membrane fatty acid composition and its overall fluidity when exposed to different temperatures. The PEF lethal and sublethal effects were assessed, and results suggested that the degree of inactivation depended on the cell membrane structure, electric field strength and treatment time. The PEF inactivation kinetics including lethal and sublethal injury fractions were fitted with non-linear Weibull distribution, suggesting that inactivation of the first log cycle of S.
