Category: Assay Development and Screening
Fundamental processes in living cells are controlled by proteins, often acting through protein-protein interactions (PPIs) on other protein partners. Alterations in PPIs are linked to many diseases and so are of increasing interest as potential drug targets. However, analyzing PPIs is challenging as is drug screening for small molecules inhibiting PPIs. One method that allows PPIs to be quantified is Bioluminescence Resonance Energy Transfer (BRET) which, in contrast to Förster Resonance Energy Transfer (FRET), does not require donor photo-excitation, circumventing autofluorescence and photo-toxicity issues. A drawback of luciferases currently used for BRET experiments is their relatively low bioluminescence-intensity, making image-based approaches challenging. Here, we present a high-content imaging application of BRET experiments using the Operetta CLS™ high-content analysis system and Harmony high-content imaging and analysis software. Nanoluciferase (Nluc) was used as donor in combination with either YFP or HaloTag 618 as acceptor. In this study, we found that serum-reduced medium improved the signal-to-background ratios and that high Nluc substrate concentrations can have a negative effect on the cells. Time series studies revealed that, despite the decay of bioluminescence signal over time, the BRET ratio remained constant. Therefore, sensitivity-optimized high-content imaging systems equipped with automated water immersion high NA objectives in combination with sensitive low noise cameras enable live cell BRET experiments in a 96-well plate format and robust PPI quantification. These results show that BRET imaging assays may be used in future for secondary drug screening assays.
Team Leader Biological Applications
Hamburg, Hamburg, Germany
As Team Leader of the Biological Applications Team at PerkinElmer in Hamburg Germany, Dr. Alexander Schreiner is responsible for developing applications for PerkinElmer’s high content screening systems. He holds a doctorate in Biology (molecular cell biology) from the Goethe University in Frankfurt. During his PhD he worked on the identification and analysis of protein-protein interactions. Following a postdoc period in the lab of Prof. Starzinski-Powitz in Frankfurt where he worked on the analysis of unusual long signal peptides he moved to the UK to work as a postdoc at the Cancer Research UK Cambridge Research Institute in the group of Prof. Fiona Watt, investigating the proliferative effect of aberrantly expressed integrins in the interfollicular epidermis. After this he worked in in the Light Microscopy Facility of the same Institute where he provided support and training for the different microscope systems within the facility.
Senior Application Scientist
Joe is instrumental in strategic customer support through teaching, training, and collaborations at PerkinElmer Cellular Imaging and Analysis group. He brings over 20 years of experience in high content screening technology from academia (Duke University and The Ohio State University), pharmaceutical industry (Abbott Laboratories and Sphinx Laboratories, Division of Eli Lilly & Company), and biotechnology (The Hamner Institute for Health Sciences and ScitoVation LLC). Joe has extensive experience in cell based technologies from flow cytometry, confocal microscopy and computer-assisted automated microscopy studying cancer, immunology, neurodegeneration, and toxicology. Joe has published several research articles and book chapters in High Content Imaging field, and is an author and co-editor to the NIH/NCATS Assay Guidance Manual. Joe was a co-founder and first President of Society for Biomolecular Imaging and Informatics (SBI2) and is a co-editor of a recent book “High Content Screening: A Powerful Approach to Systems Cell Biology and Drug Discovery”.