Adoption Of High Content Screening At High Throughput Screening Laboratories.
Over the past five years, a majority of HTS laboratories have adopted high content screening (HCS) in their operations. As HTS laboratories have sought more biologically-relevant assays, cell-based assays and high content screening technologies have become more widespread.
HighTech Business Decisions’ latest report, (High Content Screening 2013: Expanded Use and Improved Technologies), shows the adoption rate of HCS has increased over the past five years. In 2012, 61% of the HTS laboratories incorporated high content screening in their operations, compared to 40% in 2007 (Figure 1).
Improvements in throughputs, system capabilities, data handling and analysis have to increase the adoption of high content screening. While barriers to adoption remain (eg, costs, throughput, etc), both high throughput screening laboratories and their suppliers continue to dedicate resources to improve high content screening technologies.
While high content screening adoption has increased over the past five years, its rate of adoption has not been uniform across the various types of organisations that operate high throughput screening laboratories. In order to obtain a better understanding of the adoption of high content screening technologies by high throughput screening laboratories, we have segmented the high throughput screening laboratories into three different categories based on the type of organisation to which they belong.
For our analysis, the high throughput screening laboratories are categorised into three segments:
a) academic or government-sponsored laboratory
b) pharmaceutical and biotechnology companies
c) contract research organisations
We define academic high throughput screening laboratories as those that operate under either a university or a government entity. Pharmaceutical and biotechnology high throughput screening laboratories belong to innovative drug companies developing therapeutics or diagnostics. The third segment includes contract research organisations (CRO) that provide fee-forservice screening to clients.
From our study, more than three-quarters of the academic laboratories have adopted high content screening technologies, while slightly over half of the pharma/biotech high throughput screening laboratories use high content screening technologies in their high throughput screening operations. While a majority of academic and pharma/biotech has adopted some high content screening technologies, a minority of contract research organisations uses high content screening technologies.
From our study, approximately one-quarter of the contract research organisations use high content screening technologies in their laboratories (Figure 2).
HCS activities in HTS operations
For the high throughput screening laboratories that have adopted high content screening technologies, slightly less than half of those high throughput screening laboratories use high content screening in multiple areas of drug discovery (Figure 3).
Most high throughput screening laboratories run high content screens for secondary screens or hit validation (84%), while 48% of the high throughput screening laboratories use high content screening for primary screening. Other areas where high content screening is used include lead optimisation, compound profiling and toxicity studies (Figure 4).
For those high throughput screening laboratories using high content screening, there has been an increase use of high content screening in both primary and secondary screening over the past five years (Figure 5).
The proportion of high throughput screening laboratories using high content screening technologies for both their secondary and primary screens has increased considerably over the past five years. In 2012, 84% of the high throughput screening laboratories used high content screening for secondary screening, compared to 53% in 2007. Similarly, 48% of the high throughput screening laboratories used high content screening for primary screening activities in 2012, compared to 27% in 2007.
Below are selected comments from directors at leading high throughput screening laboratories regarding the use of high content screening in their operations. “We use high content screening more in the hit validation stage when we want to look at what the compound is doing in more detail. It comprises about 10% of our screening at the moment with secondary and ADME-Tox screening the bulk of the effort. We have all the technology we need and I anticipate we will use high content screening more as phenotypic screening increases.” (Pharma/Biotech HTS Lab)
“We use high content screening in a number of different ways. We have to be careful because it is such a commitment to assay development and image analysis. We don’t want to use high content screening if we can use something else instead. We use it for follow up of morphology types of assays. They are sensitive for measuring activity in primary and iPS cells. Imaging is a good readout for neuronal cells and T-cells.
We use high content screening for lead optimisation, follow-up and primary screens of targeted libraries, for example, repurposing FDA-approved drugs. It is not so good for looking for new chemistry. But, is it worth it? The trend in pharma is high content screening seems to be going down a little. It needs to be used for the right indication.
In the future, what needs to happen is the equipment needs to get cheaper so that it can inundate government and university biology labs so more and better assays can be developed. Then we will finally see more penetration of high content screening in drug discovery. We need the biologists to explore this type of capability in disease-relevant cells with better software and processing power.” (Academic AS)
“We have used high content screening for primary screens as well as secondary assays and for cytotoxicity studies to characterise our library. In the next five to 10 years, we will increase the number of phenotypic assays we do. We are interested in collecting data on a per cell basis and measuring multiple parameters.” (Academic HTS Lab)
“We only use high content screening for secondary assays. Sometimes high content screening is the only real readout we can use, we did not have any other method to assay the target. We also use it for different projects outside screening, for example, we will use the microscope to see if we are staining the cells properly.” (Pharma/Biotech HTS Lab)
While there is an increase use of high content screening, several high throughput screening laboratory directors see barriers to its continued adoption. Most of the barriers associated with the adoption of high content screening relate to the costs and benefits of high content screening compared to traditional screening technologies.
As noted by one HTS Director: “We use other options first. High content is only used for secondary screens to show the compound does what it should do in the cell. High content screening is important in target discovery. We have just started to use it for some primary screening but it is hard to judge the benefit as of yet. We use high content screening to have additional approaches, additional to the target-based approach. We were recently considering acquiring additional capabilities but we made a strategic decision to use what we have, so now if we want a different approach to a target, high content screening is the way we will handle it.”
In HighTech Business Decisions’ study, the high throughput screening directors discussed the steps they or their suppliers have taken to overcome the barriers to adopting high content screening. Most high throughput screening directors noted improvements in both software and hardware. On the software side, most HTS directors have seen improvements in both data management and analytical methods. On the hardware side, the HTS directors note major improvements in the usability of the equipment and higher screening throughputs. A summary of the steps taken to overcome the barriers to adopting high content screening is shown in Table 1.
The industry continues to demand improvements in high content screening, and suppliers are working to provide new tools that will further reduce the barriers to adoption of high content screening for drug discovery. These improvements encompass equipment, data management and consumables.
For example, Molecular Devices introduced the ImageXpress® Micro XL Widefield System. This new instrument is equipped with a sCMOS camera offering three times the image capture area.
“The increase in field-of-view translates to fewer images needed per well and faster imaging speed, said Dr Grischa Chandy, Product Manager, Cellular Imaging at Molecular Devices. “In addition, the system provides a stable solid-state light source plus environmental control and fluidics options, delivering a robust platform that meets the high throughput demands of a screening laboratory.”
Similarly, Thermo Fisher Scientific is looking at new technologies in hardware, software and in informatics which address the coming trends and current bottlenecks in high content screening.
“We are looking at how to make software more automated and easier to use, but maintain the flexibility and power that High Content can provide,” said Scott Keefer, Manager, Product Management, Cellular Imaging Analysis at Thermo Fisher Scientific. “We are also focused on providing the most robust and scalable platforms so screening facilities are more productive. The CellInsight NXT provides throughput, assay breadth and the robustness necessary to bring High Content more into primary screening facilities. These tools are all connected by BioInformatics tools that enable users to make decisions about their compounds more rapidly and in the context of other assay data.”
As previously noted, a major barrier to the adoption of high content screening technologies has been the management of data and that data management, which has been a major constraint in screening operations. “Historically, analysis and management of high content screening images and the resulting data has been the domain of software packages attached to the high content imagers,” said Dr Stephan Heyse, Head of Genedata Screener® Business Unit.
“However, such data analysis software bundled with high content screening instruments was not designed for higher throughput – it did not keep pace with instrumentation output from automated assays. Additionally, it was not designed to integrate with, for example, other high content screening instruments, other image analysis packages, or with corporate screening analysis workflows and data management systems. This created an high content screening analysis and data management bottleneck. To address these issues, Genedata Screener® was designed. In 2012, we added support for direct analysis of cell population data as part of the screening data analysis, which enables scientists to interactively define and analyse cell populations for complete screening experiments, which I believe to be an industry first.”
Molecular Devices has also introduced new tools for data management. “On the software front, Molecular Devices launched MetaXpress® Software 5.0 in summer 2012,” said Dr Chandy. “This latest release empowers users to create complex analysis using the Custom Module Editor. The new interface guides users through a step-by-step creation of custom analysis, such as identifying objects within objects, creating morphometric classifiers for shape analysis and analysing transmitted light images. Users can specify which responses to detect and which measurements to report out, saving unnecessary analysis time.”
Other improvements being made in data handling comes from De Novo Software which has released FCS Express™ Flow and Image Cytometry software package with the option for a High Content Analysis add-on. “The high content screening add-on allows high content customers to quickly analyse and make sense of their flow and image cytometry data while easily allowing the creation of high quality exports to PowerPoint, Excel and other lab information systems,” said Sean Burke, Product Manager at De Novo Software.
“With FCS Express Plus, customers have the added benefit of combining high content screening Flow and Image Cytometry analysis in one seamless package.” De Novo Software has also been working with industry leaders such as PerkinElmer, Molecular Devices and Thermo Fisher to provide direct compatibility of imaging data generated by their high content screening devices with FCS Express.
Suppliers are also making improvements in consumables and reagents. For example, Corning has developed microplates that improve high content screening imaging and throughput. “At Corning, we continuously strive towards improving efficiencies and developing new products and technologies for life science researchers,” said Dr Todd Upton, Commercial Technology Manager, Corning Life Sciences.
“We have developed and launched two glass bottom microplates (half area 96 well and 384 well) especially designed for high content screening applications. The high optical-quality and scratch resistant glass bottom microplates are ideal for performing high-content assays using imaging systems. The glass bottom flatness of <50μm ensures planarity for imaging devices, reduces autofocus time and increases throughput. We are now gearing up for a summer 2013 launch of superior quality COC (Cyclic Olefin Copolymer) film-bottom microplates to complement the glass bottom high content screening microplate product line. Both glass and COC bottom offer unique advantages of low auto-fluorescence and low diffusion of fluorescent detection; therefore, leading to high signals and low background. These attributes are particularly advantageous in enabling assays that typically have low emission intensity, therefore, expanding the applicability of high content imaging.”
There has also been improvements in the development of reagents for use in HCS. “We have consistently validated new reagents on at least one high-content platform. Examples include CellRox (oxidative stress) and CellEvent (apoptosis). We have also generated data supporting the utility of established reagents in a high-content setting, for instance Alexa Fluor® labelled phalloidin actin markers,” said Dr Magnus Persmark, Senior Product Manager, Imaging, at Life Technologies.
Future use of high content screening
The use of high content screening will continue to continue to increase. Forty-four percent of the high throughput screening Directors in our study expect to increase their use of high content screening at their laboratories. For high throughput screening laboratories that do not currently use high content screening, one-third of the high throughput screening Directors surveyed in our study expect to add high content screening in the coming years.
Furthermore, the high throughput screening Directors, on average, plan a 13% increase in the number of wells read per week over the next two years. In addition, there continues to be interest in using high content screening for primary screens. Selected comments regarding adoption of high content screening, as provided by high throughput screening directors surveyed are shown below:
“We don’t have high content screening yet, but we are investigating it seriously. We plan to bring in a system within six to 18 months.” (Pharma/Biotech HTS Lab)
“We are just starting to be interested in high content screening, but have not yet run a screen. We will use high content screening as a follow- up to a secondary assay. We will start running high content screening primary screens within six months.” (Pharma/Biotech HTS Lab)
“We utilise HCS only in secondary screening after primary screening, but as technology improves, costs decrease, and throughput increases, we anticipate moving high content screening more to a primary screening mode.” (Pharma/Biotech HTS Lab)
We use high content screening in early screening programmes, lead discovery, or hit identification, as just one technology, in addition to other technologies. We anticipate we will expand the amount of high content screening in future. Clearly, if we run more phenotypic screens, we will need to run more high content screening.” (Pharma/Biotech HTS Lab)
The majority of high throughput screening laboratories have adopted high content screening technologies into their laboratory operations. High content screening is primarily being used in secondary screening operations, but there continues to be a trend toward its use in primary screening. Over the past five years, both high throughput screening laboratories and their suppliers have worked to reduce these barriers to adoption. Yet, for many high throughput screening Directors, there continues to be significant barriers for its continued adoption.
Those barriers include costs, the current state of analytical software and data management, throughputs and the quality of antibodies and labels. Despite these barriers, high content screening will continue to grow as the number of high throughput screening laboratories continue to adopt high content screening technologies and expand its use. DDW
William Downey is President and Dr Jennifer Hartigan is the senior scientific at HighTech Business Decisions, a consulting firm specialising in customised market analysis, industry reports and customer loyalty studies for suppliers serving the pharmaceutical and biotechnology industries. The company recently published the report High Content Screening 2013: Expanded Use and Improved Technologies. www.hightechdecisions.com.