Synthesis of Intrinsically Disordered Fluorinated Peptides for Modular Design of High-Signal F MRI Agents.

F MRI is valuable for in vivo imaging due to the only trace amounts of fluorine in biological systems. Because of the low sensitivity of MRI however, designing new fluorochemicals remains a significant challenge for achieving sufficient F signal. Here, we describe a new class of high-signal, water-soluble fluorochemicals as F MRI imaging agents.

"Measure Your Gradient": a new way to measure gradients in high performance liquid chromatography by mass spectrometric or absorbance detection.

The gradient produced by an HPLC is never the same as the one it is programmed to produce, but non-idealities in the gradient can be taken into account if they are measured. Such measurements are routine, yet only one general approach has been described to make them: both HPLC solvents are replaced with water, solvent B is spiked with 0.1% acetone, and the gradient is measured by UV absorbance.