Sensitivity analysis of the allele-specific PCR assay.

<p>(<b>A</b>) <b>Sensitivity analysis using the bacterial genomic DNA.</b> The detection limit was determined as 10 pg of bacterial DNA for <i>E. coli</i> serotypes O2 and O18 strains, and 500 pg of bacterial DNA for <i>E. coli</i> serotypes O1 and O78 strains, respectively. (<b>B</b>) <b>Sensitivity analysis using the bacterial culture.</b> The detection limit was determined as 10 CFUs of <i>E. coli</i> serotypes O2 and O18 strains, and 1,000 CFUs of <i>E. coli</i> serotypes O1 and O78 strains, respectively. Lane M: DL2000 Marker.</p

Sensitivity analysis of the allele-specific PCR assay.

<p>(<b>A</b>) <b>Sensitivity analysis using the bacterial genomic DNA.</b> The detection limit was determined as 10 pg of bacterial DNA for <i>E. coli</i> serotypes O2 and O18 strains, and 500 pg of bacterial DNA for <i>E. coli</i> serotypes O1 and O78 strains, respectively. (<b>B</b>) <b>Sensitivity analysis using the bacterial culture.</b> The detection limit was determined as 10 CFUs of <i>E. coli</i> serotypes O2 and O18 strains, and 1,000 CFUs of <i>E. coli</i> serotypes O1 and O78 strains, respectively. Lane M: DL2000 Marker.</p

The product profiles of <i>E. coli</i> serotypes O1, O2, O18 and O78 strains amplified using the allele-specific PCR.

<p>Lane M: DL2000 DNA Marker; O1, O2, O18 and O78 represent PCR products for O1, O2, O18 and O78 strains respectively. Lane 1: APEC O1 strain; Lane 2: APEC strain DE47; Lane 3: APEC strain DE14; Lane 4: APEC strain DE17; Lane 5: APEC strain RS218; Lane 6: APEC strain CE66; Lane 7: APEC strain DE48; Lane 8: APEC strain DE65; Lane 9: Negative control.</p

The <i>rfb</i> gene clusters of <i>E. coli</i> serotypes O1, O2, O18 and O78 strains.

<p>The black arrows correspond to <i>gnd</i> and <i>galF</i> genes. Grey arrows correspond to <i>rfb</i> gene cluster and the gene names are <i>italic</i> indicated. The length of <i>rfb</i> gene cluster was also shown. In the PCR reaction system, the universal forward primer was used for all the sero-typing amplification with specific reverse primers. The bold lines below the <i>gnd</i> gene indicate the size of the PCR products for different <i>E. coli</i> serotype strains, which allow the differentiation of the O types. Primers and their locations were also indicated.</p

Bacterial strains used in this study.

a<p>CVCC, Chinese Veterinary Culture Collection Center, China.</p>b<p>ATCC, American Type Culture Collection, USA.</p

Primers used in this study.

a<p>The primers were designed based on the gene sequences of <i>wekO</i>, <i>wekS</i>, <i>wekW</i> and <i>wzx</i> in the <i>rfb</i> gene cluster of respective serotypes of <i>E. coli</i> strains.</p

Crossover from 3D to 2D Quantum Transport in Bi₂Se₃/In₂Se₃ Superlattices

The topological insulator/normal insulator (TI/NI) superlattices (SLs) with multiple Dirac channels are predicted to offer great opportunity to design novel materials and investigate new quantum phenomena. Here, we report first transport studies on the SLs composed of TI Bi₂Se₃ layers sandwiched by NI In₂Se₃ layers artificially grown by molecular beam epitaxy (MBE). The transport properties of two kinds of SL samples show convincing evidence that the transport dimensionality changes from three-dimensional (3D) to two-dimensional (2D) when decreasing the thickness of building block Bi₂Se₃ layers, corresponding to the crossover from coherent TI transport to separated TI channels. Our findings provide the possibility to realizing “3D surface states” in TI/NI SLs