Sources of endocrine-disrupting compounds in North Carolina waterways: a geographic information systems approach.

The presence of endocrine-disrupting compounds (EDCs), particularly estrogenic compounds, in the environment has drawn public attention across the globe, yet a clear understanding of the extent and distribution of estrogenic EDCs in surface waters and their relationship to potential sources is lacking. The objective of the present study was to identify and examine the potential input of estrogenic EDC sources in North Carolina water bodies using a geographic information system (GIS) mapping and analysis approach. Existing data from state and federal agencies were used to create point and nonpoint source maps depicting the cumulative contribution of potential sources of estrogenic EDCs to North Carolina surface waters. Water was collected from 33 sites (12 associated with potential point sources, 12 associated with potential nonpoint sources, and 9 reference), to validate the predictive results of the GIS analysis. Estrogenicity (measured as 17ß-estradiol equivalence) ranged from 0.06 ng/L to 56.9 ng/L. However, the majority of sites (88%) had water 17ß-estradiol concentrations below 1 ng/L. Sites associated with point and nonpoint sources had significantly higher 17ß-estradiol levels than reference sites. The results suggested that water 17ß-estradiol was reflective of GIS predictions, confirming the relevance of landscape-level influences on water quality and validating the GIS approach to characterize such relationships.

A rainbow of fluoromodules: a promiscuous scFv protein binds to and activates a diverse set of fluorogenic cyanine dyes.

Combined magnetic and fluorescence cell sorting were used to select Fluorogen Activating Proteins (FAPs) from a yeast surface-displayed library for binding to the fluorogenic cyanine dye Dimethyl Indole Red (DIR). Several FAPs were selected that bind to the dye with low nanomolar Kd values and enhance fluorescence more than 100-fold. One of these FAPs also exhibits considerable promiscuity, binding with high affinity to several other fluorogenic cyanine dyes with emission wavelengths covering most of the visible and near-IR regions of the spectrum. This significantly expands the number and wavelength range of scFv-based fluoromodules.