The Echo® MS System is an exciting new platform that dramatically speeds sample analysis for quantitative MS studies. Because of its unique and innovative technology, the system can analyze samples faster than ever before—but without the need for LC.
With traditional LC-MS, the column provides a means for sample concentration, clean-up and separation. Chromatographic conditions are carefully optimized for the fastest elution times while still maintaining good quantitative results.
With the Echo® MS System, an Acoustic Droplet Ejection (ADE) is used with an Open Port Interface (OPI) to deliver sample to the electrospray source of a mass spectrometer. This process is fast—VERY fast, with speeds of up to 3 samples per second. But without LC, can good analytical performance be achieved? And would performance degrade with very complex or “dirty” samples?
To evaluate the reproducibility of the Echo® MS System, researchers at SCIEX analyzed 100 nM dextromethorphan in 10% methanol in water in every well of a 384 well plate. As shown in the technical note Rapid MS/MS analysis with Acoustic Ejection Mass Spectrometry (AEMS), MRM peak areas of 1.98% were achieved across all 384 wells. Additionally, all 384 wells were acquired in just under 7 minutes—barely enough time for a coffee break!
What about different amounts of sample? In the same study a “droplet ladder” of 1 to 20 droplets was generated from one of the dextromethorphan sample wells with 10 replicates for each. The ability to specify the number of droplets is analogous to an injection volume in standard HPLC work. Here the %CV obtained for the 10 replicates across the droplet ladder was <3% with excellent linearity and R2 of 0.9997.
Sounds great so far, but what about dirtier samples or challenging matrices? With traditional LC-MS, the column effectively cleans up the sample prior to elution. What happens with the Echo MS System?
In the technical note True high throughput bioanalysis using the Echo® MS System, 3 different sample preparation methods were used to see how a complex matrix would affect the quality of the data. Here, concentration curves for fentanyl were generated from protein precipitated plasma, 1:1 plasma in water and untreated plasma. Incredibly, the best performance was observed for the samples in the untreated plasma.
Better results directly from plasma? How can that be?!
The reason lies in the dilution effects that are created with the OPI. When the droplet from the ADE enters the OPI, solvent sweeps the droplet to the mass spectrometer. This built-in “dilute-and-shoot” process minimizes matrix suppression effects that would normally result from injecting straight plasma into the MS. The result is higher ionization efficiency for analytes and excellent sensitivity—all without any sample preparation.
As a further test of the ability to measure analytes directly from complex matrices, angiotensin was analyzed directly from a yeast fermentation broth at 25, 30 and 50 mg/L at dilutions of 1x, 10x and 100x. As demonstrated in the technical note Rapid quantitative analysis of fermentation broth samples to assess efficiency of engineered yeast strain turnover, very high reproducibility with consistent and precise quantification was observed across all dilutions, even for the least dilute sample. Even with such a complex matrix, virtually no sample preparation was required. In the field of synthetic biology, where strain selection can be time consuming and tedious, minimal sample prep and faster screening means faster strain selection and an end to a costly bottleneck in the workflow.
To learn more about this truly game-changing innovation that lets you RUN FAST with incredible performance, visit the Echo® MS System website for more information.
Run so fast, all they hear is your echo. You’ll be glad you did … you’ll be glad you did … you’ll be glad you did.
This blog is part 3 of a 3-part series on the Echo® MS System. Read part 1 (“How fast is fast? The Echo® MS System sets the record”) and part 2 (“Scale it up! The Echo® MS System delivers unprecedented levels of productivity”).