WHAT DOES THE NEXT GENERATION SEPARATION TECHNOLOGY FOR MS BASED OMICS LOOK LIKE?
Three years ago, the Evosep One technology was developed to target the growing need for high-throughput solutions for clinical and large-scale proteomics. Striking the right balance in performance, delivering both sensitivity, speed and robustness is an essential part of the Evosep One technology.
In a recent study we asked users what they saw as their main reason for using the Evosep One system, generating a word cloud to visualize their free text answers based on the most used keywords.
Based on user answers, the top three qualities of the Evosep One is speed, robustness and high throughput.
We believe that mass spectrometry-based omics analysis will become a widespread, broadly applicable clinical technique and we have gathered our thoughts on how our technology is designed to bring the community closer to the clinic.
STRIKING THE RIGHT BALANCE
Clinical analyses almost invariably require relatively high throughput and rugged equipment with simple processes. At present, proteomics analysis is relatively slow and high maintenance. Clearly, the largest performance gap lies not with the mass spectrometers but with the sample purification and separation steps that are immediately prior to MS.
Therefore, we have decided to radically innovate the separation technology and make – almost from scratch – something that is specifically tailored for clinical omics. In brief, our first design target is a platform that separates omics samples @ 1μL/min into a mass spectrometer, while enabling 24/7 operation @ 200 samples/day. (please read below why this is our target)
1: SENSITIVITY VS. ROBUSTNESS
While clinical omics must be robust, it must also be sensitive enough to allow detection of those components that really matter. Optimum sensitivity in electrospray is obtained at the lowest possible flow rate, while optimum robustness requires flowrates that are three order of magnitude higher.
It seems that most mass spectrometer inlets have a sweet spot around 1μL/min – 1.5μL/min where one may obtain both everyday robust operation and sensitivity that is close to nanoLC performance. We have therefore decided to optimize our designs for this flow range.
2: SPEED VS. ROBUSTNESS – FAST AND ROBUST CLINICAL PROTEOMICS
Higher throughput may be obtained with higher flow rates, but again, we cannot afford to sacrifice sensitivity. So we have to achieve the necessary speed at low flow.
We have set ourselves the target of being able to run 200 patient samples per day per LC-MS system @ 1 – 1.5 μL/min. This corresponds to roughly 7 minutes per sample. Utilizing some new plumbing ideas, we have shown that this is not only doable, but we also hope to have a duty cycle above 80% even at this very high speed. Ultimately, we believe cycle times can be below 2 minutes, but at that speed, mass spectrometers are currently not fast enough to yield useful data of complex mixtures.
3: RESOLVING POWER VS. ROBUSTNESS
The last decade there has been a trend towards optimising the resolving power in chromatography by deploying higher and higher pressure. We don’t think today’s ultrahigh pressure, low-flow LC systems will ever be sufficiently robust to operate in clinical labs. We have now designed a low-pressure low-flow LC system where nearly all sample handling and gradient formation takes place at a few bar (few tens of psi) while only a single high pressure pump (running at a few hundred bar) is used to press the sample through the column towards the mass spectrometer. This new low-pressure design promises to be virtually leak proof and exhibit very little wear and tear on its hardware.
Our end goal is to develop a system that processes crude biological samples, e.g. blood and delivers the separated omics compounds into a mass spectrometer. This will require innovation on many fronts and we are already busy with several projects that we look forward to sharing with you.