NEW YORK – Roche Diagnostics' flagship LightCycler qPCR system has recently been subject to a significant evolution to meet the current trends in molecular testing.
Slated to ultimately replace the LightCycler 480, the newly launched LightCycler PRO has features that Roche expects will serve customers in both the research and clinical spaces, as well as those wishing to translate research-use assays into in vitro diagnostic tests.
The new attributes of the LightCycler PRO include updated hardware and software and dedicated workflows enabling users to run research-use-only assays, as well as IVD tests, seven optical channels, and enhanced temperature control for thermal cycling.
Roche describes the PRO as having a "modern look and feel" with a 40-centimeter touchscreen, as well as remote connectivity, LIS, and ethernet connections.
Josh Lauer, head of molecular labs at Roche, said in an interview that the PRO is the first of the LightCycler qPCR systems that is designed to support both RUO and IVD testing. It can help labs that develop their own solutions to take their workflows from the translational research environment into the clinical environment, Lauer said, adding that this "is actually a first and rather unique for this family and for this type of system."
James Lee, senior international product manager of LightCycler systems at Roche, explained that customers who wish to alter their assays or assay parameters in the RUO testing workflow mode can attach a PC to the LightCycler instrument. "Utilizing the software on the separate computer, you can change the parameters or the run conditions," Lee said.
Within the IVD workflow, the system operates like a kiosk with a touchscreen, Lee said. "Everything is pretty much locked down — you just basically want to enter your samples, and you get your results," he said, although customers can also tinker with parameters in this mode by using the external computer, as well.
For lab-developed test development, customers can also simply control the instrument to run that test using the external PC and the software. "And then, once they have locked down the workflow, they can submit that LDT to have an IVD label if they wish to do so," Lee said.
The original LightCycler qPCR system was developed at the University of Utah and Idaho Technology, a firm that would eventually become BioFire Diagnostics. The tech was licensed to Boehringer Mannheim in 1997, then that firm was acquired by Roche, with the Roche LightCycler system officially launching in 1998.
Roche's legacy LightCycler 480 debuted in 2005, and a few years later was experiencing double-digit sales growth, according to the firm. The 480 system has six color channels, while the smaller, less expensive LightCycler 96 that Roche subsequently launched in 2012 has four. The company also recently expanded into digital PCR with the six-color Digital LightCycler.
The addition of a seventh optical channel in the LightCycler PRO is intended to further support trends toward more multiplex qPCR testing and syndromic panels. "For the last 30 years, the LightCycler served customers even without that seventh channel, but we're excited to offer this extra bit of flexibility to users as we're seeing more and more of these multi panels being constructed," Lee said.
While customers can run assays from any vendor on the PRO system, Lee noted that Roche's wholly owned subsidiary TIB Molbiol markets singleplex assays that enable the creation of multiplex tests, such as respiratory infection panels.
Called LightMix Modular Assays, these arrive in separate tubes, Lee said, and customers can mix them together to create bespoke tests. Roche previously collaborated with TIB Molbiol for nearly two decades before acquiring the Berlin, Germany-based company in late 2021.
Lauer highlighted that TIB Molbiol has developed more than 200 RUO assays and markets 60 that are CE-IVD marked. "That flexibility pairs really well with the LightCycler PRO system," he said.
The LightCycler PRO was in development since before the coronavirus pandemic, Lauer said, with this evolution of the LightCycler 480 inspired in part by in-depth conversations with customers. "Increasingly, we see that labs want to know that they have a path to take some of their RUO workflows and tests that they've developed and evolve with the market and with regulations into more clinical spaces," Lauer said.
In the past, "lots of labs have bought LightCycler 480s and then looked at IVD platforms" for regulated testing, he said. But the LightCycler PRO "offers a bridge to labs where they can do both with one system."
Lee further noted that the plan is for TIB Molbiol to take their assays into the IVD-R pathway, "and at that point, the LightCycler PRO becomes their exclusive instrument to deploy these assays into."
The PRO currently has CE-IVD marking and is under US Food and Drug Administration 510(k) exempt status. The LightCycler PRO is also "IVD-R ready," which Roche said puts it in a great position to expand its assay menu through TIB Molbiol in the molecular testing space.
The thermal cycling in the LightCycler PRO incorporates what is dubbed a Vapor Chamber Mount that Lee said is akin to the heat pipe technology used to control temperature in semiconductors.
Historically, solid aluminum blocks in thermal cyclers tended to have slight temperature difference at the edges, where the metals interface with the environment, Lee said. With the Vapor Chamber Mount, the block is hallowed out and a vapor layer is used to heat and cool the block and the samples together, he said. This eliminates some of the mass of the block, which in turn reduces the energy requirements.
"And, because the vapor circulates, it maintains a very uniform temperature across the sample and across the plate," Lee added.
In terms of marketing, Lauer said that Roche will target clinical customers with the LightCycler PRO, but it can also serve a variety of customers, including those who focus solely on research.
And, although some investment analysts in the life science tools space have recently pointed out a downturn in instrument purchasing after a pandemic spending spree, Lauer said the PRO has some advantages here, as well.
Given labs' constrained budgets, the PRO can help them narrow their capital expenditures "by allowing them to get much more utility out of a single instrument," he said. "Our customers have been asking us for that flexibility even before COVID, so in good times or bad, we view this as just trying to respect labs' costs so that they can only buy one instrument instead of multiple," Lauer added.
Lauer declined to comment on the specific cost of the LightCycler PRO but said "it's well known if you look out in the market that the LightCycler  is a relatively low-cost instrument versus some other platforms."
He also said that using the PRO's RUO/IVD flexibility in a benchtop system will also likely lower costs for customers as they won't need separate, dedicated research and IVD test systems.
Evolution and competition
"The life cycle of the LightCycler has been impressive," said Carl Wittwer, the primary inventor of the original technology.
Debuting as a research instrument, the system introduced melting analysis and SYBR Green I to real-time PCR, which in turn served to democratize the then-novel approach and allow more extensive options for probes and dyes, Witter said. Now, "the LightCycler PRO continues this evolution into the clinical laboratory," he said.
"For clinical labs, the ability to develop tests in a research mode, followed by seamless transition to an on-line diagnostic test, is a core advantage," said Witter, who got to take a look at the PRO instrument at the Association for Molecular Pathology conference earlier this month.
Temperature control is "the most important characteristic of real-time PCR instruments with rapid turnaround times," Wittwer said, and the Vapor Chamber Mount in the PRO "minimizes temperature anomalies across the plate while allowing gradient thermal cycling for assay optimization."
Mikael Kubista, head of the Laboratory of Gene Expression at the Czech Academy of Sciences, said that data showing the impact of the Vapor Chamber Mount on precision of testing would be helpful in the future, and Roche's Lee said that the firm plans to provide customer testimonials and specs going forward.
For Kubista, a main attractive feature of the PRO is that it can analyze 100 microliter samples in the 96-well plate mode, which is considered a large volume. "In diagnostics, sensitivity is usually important, and it is proportional to the sample volume analyzed," he said.
On the other hand, the opposite extreme low volume of 5 microliters when using the 384-well plate setup has the advantage of saving cost when sensitivity is not an issue or when screening many samples, he said, such as during the peaks of the COVID-19 pandemic.
The seventh optical channel on the LightCycler PRO might be most advantageous should Roche and TIB Molbiol or third-party vendors begin offering seven-plex assays in the future, Kubista said, because "designing and validating high multiplex assays is time-consuming and costly."
Stephen Bustin, a professor of molecular medicine and lead of the molecular diagnostics unit at Anglia Ruskin University in the UK, concurred that the challenges of seven-plex assay design might limit the utility of all seven channels for research, although it could be useful for detection of multiple pathogens, for example, in a syndromic panel test.
In the diagnostics lab space, "there will always be a need for benchtop, high-throughput diagnostic instruments, whereas researchers want inexpensive, flexible hardware and user-friendly software," Bustin explained.
"Most instruments on the market today perform well and generate consistent, reliable, and reproducible results," Bustin said, with the main distinction among different systems being the size and the cost. Software also "ranges from excellent to very frustrating," he said, noting that he places Bio-Rad's Opus system software in the "excellent" category, for example.
In addition to Roche's LightCycler PRO, Kubista noted that there are other systems that can operate in both RUO and IVD modes, such as the Thermo Fisher Scientific QuantStudio 5 Dx and QuantStudio 7 Pro Dx. Earlier this year, Thermo described plans to bring the company into the IVD regulated space with clinical solutions in part through the launch of a line of assay kits including an initial menu of 37 CE-IVD marked kits for the QuantStudio 5 Dx and the 7 Pro Dx systems.
Kubista expects "more to come" in this space of dual IVD/RUO systems but noted that standalone qPCR instruments typically still require a separate instrument for extraction. Instruments with integrated extraction and qPCR typically only run in IVD mode, although the BD Max system might be considered an exception to this rule.
For a standalone qPCR instrument that can operate in IVD mode, it is possible that third parties can develop tests that they take through approval for the platform, Kubista said, which further increases the regulated content for the system.
And, the PRO's RUO and IVD modes are a "great advantage for laboratories interested in performing non-routine diagnostics," Kubista said. "It can take years before approved IVD tests become available for new agents," he said, so a rapid lab response to new pathogens requires laboratories to develop tests or purchase and validate RUO kits for internal diagnostic use.
"With the new LightCycler PRO, the laboratory does not have to change instruments when upgrading the initial LDT/RUO analysis to IVD," he said.