More than 2,500 human miRNAs are potentially significant biomarkers. Moreover, the use of blood circulating miRNAs as disease-specific biomarkers is one of the most valuable outputs for translational and clinical research. Nevertheless, such an analysis still requires the selection of robust technologies, huge R&D work and reproducibility studies.

During the latest AACR Meeting (April 2015, Philadelphia – USA), Nadia Normand, R&D manager at tebu-bio’s laboratories (Le Perray en Yvelines, France), presented a poster comparing various platforms for measuring circulating miRNAs. It was the opportunity to further demonstrate the robustness of  the miRNA 3D-Gene® microarray-based platform (Toray Industries).

To know more about the comparison, follow this link to access to the poster:

Mennesson E. et al. “Comparison of different highly sensitive miRNA array platforms for the investigation of circulating cell-free microRNAs in blood” (2015) – Poster AACR.

Mammalian expression constructs for certain genes such as human c-KIT are notorious for undergoing frequent recombinations during cloning and transformation steps in molecular biology labs. Experts suggest that certain genes are “toxic” to bacteria thus leading to a situation in which recombined plasmids are favored. While the molecular mechanisms for this toxicity may be unclear, the end result is that efforts to amplify, subclone, mutate, or make derivative vectors often result in a new plasmid with unwanted sequence errors.

Source: http://en.wikipedia.org/wiki/Agar_plate

Online science discussion forums such as ResearchGate include a variety of strategies proposed by researchers experiencing this kind of plasmid instability. Suggestions include advice such as culturing the bacteria at room temperature rather than 37°C, culturing on plates rather than in flasks, using low copy number EPI400 competent cells, picking the small colonies rather then the large ones from the LB plate, replacing the ampicillin resistance cassette to prevent satellite colonies (so you can see the small colonies), or using a Gateway vector.

But which methods work best?