Newly engineered cyan fluorescent proteins with enhanced performances for live cell FRET imaging.

Cyan fluorescent proteins (CFPs) derived from Aequorea victoria green fluorescent protein are the most widely used Förster resonant energy transfer (FRET) donors in genetically encoded biosensors for live-cell imaging and bioassays. However, the weak and complex fluorescence emission of cyan variants, such as enhanced cyan fluorescent protein (ECFP) or Cerulean, has long remained a major bottleneck in these FRET techniques. Recently, several CFPs with greatly improved performances, including mTurquoise, mTurquoise2, mCerulean3, and Aquamarine, have been engineered through a mixture of site-directed and large-scale random mutagenesis.

Minimum set of mutations needed to optimize cyan fluorescent proteins for live cell imaging.

Cyan fluorescent proteins (CFPs) are widely used as FRET donors in genetically encoded biosensors for live cell imaging. Recently, cyan variants with greatly improved fluorescence quantum yields have been developed by large scale random mutagenesis. We show that the introduction of only two mutations, T65S and H148G, is able to confer equivalent performances on the popular form ECFP, leading to Aquamarine (QY = 0.

The single T65S mutation generates brighter cyan fluorescent proteins with increased photostability and pH insensitivity.

Cyan fluorescent proteins (CFP) derived from Aequorea victoria GFP, carrying a tryptophan-based chromophore, are widely used as FRET donors in live cell fluorescence imaging experiments. Recently, several CFP variants with near-ultimate photophysical performances were obtained through a mix of site-directed and large scale random mutagenesis. To understand the structural bases of these improvements, we have studied more specifically the consequences of the single-site T65S mutation.

Gas diffusion flow injection determination of thiomersal in vaccines.

A new simple gas diffusion flow injection method has been developed for the determination of thiomersal in biological samples. The method is based on cold vapor generation of monoatomic mercury from thiomersal reaction with acidic stannous chloride solution (0.6%) acting as reducing agent.