Proteins

The Nexi-Protein-Screen is an in vivo screening system for protein-protein interactions in yeast cells. In contrast to common protein interaction screening systems, like the two hybrid system, the Nexi-Protein-Screen detects protein interactions in the cytoplasm of living yeast cells.

This novel class of interaction screening systems was found not to be prone to false-positive signals. In fact it could be used in many cases, where the Two Hybrid System failed. We used the Nexi-Protein-Screen, successfully with a broad range of protein classes, like transcription factors, protein kinases, multifunctional proteins and domains from membrane proteins. It is very well documented from published screenings as well as from internal and customer screenings, that cytoplasmic screening systems and the Nexi-Protein-Screen are able to identify proteins, which the Two Hybrid System was not able to pick up. The Nexi-Protein-Screen is a significantly further developed screening system, which combines:

• broad and sensitive detection range
• low rate of false-positive signals
• better reliability
• high hit rates (e.g. from improved proprietary libraries)

Screening reliability

The Nexi-Protein-Screen integrates standardized biological protocols, semi-automatic robotic procedures and a proprietary laboratory information management system (LIMS) for the acquisition, storage and analysis of experimental screening data.This results in a significant increase in reliability of interaction screenings. Enhanced biological protocols implement more stringent specificity testing thus further supporting the biological significance of identified interaction partners.

Libraries

Conventional cDNA expression libraries are of very variable quality, often resulting in poor screening outcome. Nexigen developed proprietary cDNA expression libraries, which are optimised for the abundance of coding regions, representation of weakly expressed genes, and high complexity. It is possible to construct custom libraries, which reflect certain disease models or specific cellular stimulation or treatment.