FlopR: An open source software package for calibration and normalization of plate reader and flow cytometry data

The measurement of gene expression using fluorescence markers has been a cornerstone of synthetic biology for the last two decades. However, the use of arbitrary units has limited the usefulness of this data for many quantitative purposes. Calibration of fluorescence measurements from flow cytometry and plate reader spectrophotometry has been implemented previously but the tools are disjointed. Here we pull together, and in some cases improve, extant methods into a single software tool, written as a package in the R statistical framework. The workflow is validated using Escherichia coli engineered to express GFP from a set of commonly used constitutive promoters. We then demonstrate its power by identifying the time evolution of distinct subpopulations of bacteria from bulk plate reader data, a task previously reliant on laborious flow cytometry experiments. Along with standardized parts and experimental methods, the development and dissemination of usable tools for quantitative measurement and data analysis will benefit the synthetic biology community by improving interoperability.Graphical Abstract

Functionalization of chlorin e6 trimethylester towards potential amphiphilic photosensitizers for photodynamic therapy

Chlorins (dihydroporphyrins) are considered, due to their ideal photophysical properties, as attractive photosensitizers for photodynamic therapy (PDT) of cancer and other therapeutic and diagnostic applications. Chlorophyll [Formula: see text], as a naturally occurring chlorin, forms an almost unlimited renewable resource for preparation of potential biologically active chlorin photosensitizers and fluorescence markers. To achieve amphiphilic photosensitizers which might be selectively enriched in tumor cells, we addressed linkage of per se lipophilic chlorophyll derivatives with carbohydrate based hydrophilic aminopolyols.

Arginine mimetic appended peptide-based probes for fluorescence turn-on detection of 14-3-3 proteins

Development of fluorescence markers for the 14-3-3 adapter protein class.