Spotting Top Performers
High-content screening (HCS) and high-content analysis (HCA) cell-based imaging platforms offer researchers an early look at cell response, protein-protein and cell-cell interactions, and morphological and volumetric changes. Cell-based imaging can help spot top performers in a roster of pharmaceutical leads, as well as provide life science researchers a more integrated approach with which to study the fundamental processes of biology. In addition, as biophotonics applications have matured, it has also become possible to track cellular processes in the whole animal, linking cellome-level data to systems biology, and pushing screening processes to the preclinical level.
Cellomics (www.cellomics.com), a unit of Fisher Biosciences, offers a full HCS/HCA fluorescence-reporting platform that includes instrumentation, software, and reagents.
At the center of its platform are the BioApplications, a collection of HCS algorithms for analysis of various cell-biology measurements, including G-protein coupled receptor (GPCR) signaling, cell-health profiling (apoptosis/necrosis; early and late toxicity; survival of target-expressing cells), molecular translocation, analysis of cell morphology (including inter- and multi-cellular changes), neuronal profiling, and automatic identification and quantification of micronuclei.
HitKit® HCS Reagent Kits are available for all BioApplications, allowing researchers to quickly develop assays with optimal reproducibility, according to Cellomics. Each kit contains the requisite fluorescent reagents, buffers, and optimized sample-preparation protocols. The imaging systems integral to these products are the ArrayScan® and KineticScan®, HCS Readers, and the cellWoRx™ High Content Cell Analysis System. These systems are optimized for both fixed-endpoint and live-cell kinetic studies.
Judy Masucci, Ph.D., director of marketing and sales support at Cellomics, describes the ArrayScan VTI HCS Reader as the company’s flagship HCS system, designed for the screening environment. Both ArrayScan and KineticScan “offer on-the-fly image analysis, addressing the imaging bottleneck—acquisition of images. It saves time in most cases by allowing the user to add intelligence to the image process. For instance, you can instruct the software to keep imaging until you get a hit, or count the number of hits per well. You can also implement stop criteria (useful if several wells are bad), or program rare-event assays.”
In addition, the user can build statistical analysis into the screening process, which saves post-processing time. The High Content Informatics (HCi™) suite of software “handles volumes of data, which can encompass hundreds of parameters per cell, per well, and per field.”
Dr. Masucci explains that Cellomics “has made arrangements with competitive companies to use Cellomics’ HCi platform through an interface known as HCS Gateway™. The HCi suite is comprised of a database called Cellomics® Store (for both images and data), an HCS Applications server (middleware), and the Gateway itself (instruments that talk to the middleware).”
The vHCS™ Discovery Toolbox, which is also a part of the HCi suite of software, enables users to visualize and make decisions from their data. A version of this toolbox, known as the vHCS Analysis Toolbox, can also be used in tandem with the cellWoRx system, a fully integrated HCS imaging system that is based on Applied Precision’s (www.appliedprecision.com) illumination pathway and offers four-color, rapid image acquisition, ranging from UV to IR.
For ease of use Cellomics offers turnkey solutions such as prescripted parameter settings and tailored algorithms, benefiting either the inexperienced or well-versed experimentalist.
BD Biosciences (www.bdbiosciences.com) offers an array of imaging systems, ranging from a basic microscopy package to a system designed to image live cell kinetics and other time-resolved events, looking at the cell in the context of its matrix or substrate. In the middle range of capability is the BD Pathway™ 435 series benchtop imager that offers eight excitation, eight emission, and five dichroic filter positions that can be independently controlled to produce a broad array of fluorescence detection.
Its fluorescence-based bioapplications include, among others, neurite outgrowth, protein translocation, angiogenesis, colocalization, cell cycle and 3-D confocal analysis. Phil Vanek, Ph.D., director of global marketing, explains that BD Biosciences’ approach to “bioimaging complements our flow-analysis capabilities. While cytometry is a sensitive and flexible powerhouse technology, bioimaging is helpful when cells are investigated in a contextual format—grown on novel substrates or in clusters.
“The BD Pathway 855 is a high-content platform geared to automating high-resolution functional cell-based assays,” enabling such experimentation as “fast calcium kinetic measurements, time-lapse experimentation, 3-D exploration of cell clusters, ADME and toxicity applications, and screening of antibodies.”
The company also offers the BD FACSArray™ Bioanalyzer, a fully integrated two-laser flow analyzer that can perform cellular or cytometric-bead based analysis. With over 1,500 available reagents and the ability to capture up to 15,000 events per second, the Bioanalyzer covers the full range of biological applications, including intracellular phosphorylated protein detection and cytokine analysis and cell-cycle events. The unit features a microtiter plate sampler, and is designed for use with BD’s Cytometric Bead Array (CBA) Flex Set. Dr. Vanek adds that the “customizable bead array technology enables researchers to develop their own uniquely configured experiments.”