PEAQ-ITC at PittconWe were very excited to launch PEAQ-ITC – our brand new range of Isothermal Titration Calorimetry (ITC) instruments – a couple of weeks ago with a live demonstration.  If you missed the online event, please click here to play it back.

During the Q&A session at the event, we were thrilled to receive so many questions about the new instrument.  We covered some of the questions on the day but not all of them, so this blog post addresses everything to make sure you get all the information you need. If you have a question we haven’t covered in this long list, please contact our sales team or reach out to your local Malvern representative.

Don’t forget to also take a look at these great whitepapers focusing on the capabilities of PEAQ-ITC:

Whitepaper: Use of the new MicroCal PEAQ-ITC system for measurement and characterization of a broad range of protein-LMW compound interactions

Whitepaper: Addressing the needs of drug discovery with the MicroCal PEAQ-ITC instruments

If you would like a demo of PEAQ-ITC, please click here.

If you would like a saleperson to contact you with a quote, please click here.

PEAQ-ITC Q&A

Design, Operation & Maintenance Related Questions

Q. In which way is the new design of the paddle better?

The paddle has a more severe twist, increasing mixing efficiency.

Q. Any sensitivity increase compared to ITC200?

The short term noise is improved and so the data looks better and gives confidence to the user when the signal is small. However the sample requirements are the same.

Q. With the iTC200 I had problems with syringes breaking when filling. Is the design improved in this regard?

This has had a complete redesign. There should be no more broken syringes.

Q. Does the wash module clean the cell and the syringe with detergent?

Yes, it is very thorough and moves the detergent back and forth to make sure that all potential dirt ‘pockets’ are reached and cleaned

Q. Is the new software and/or wash module compatible with the ITC200?

No, the design has been changed too much to make backward compatibility feasible.

Q. What backs up the accurate sub-nM affinity measurement?

Repeatability of result and good comparison with other techniques.

Q. Any changes for sample requirements relative to the the ITC200?  That is 200 ul for the cell and 60 ul of the syringe?

The same volumes are required.

Q. Which concentrations are required?

Typically 5-25 uM in the cell and 5-250 uM in the syringe.

Q.  I am interested in measuring protein-protein interaction. If the binding constant is about several micro molar, how much protein do I need for both?

10-20 uM in the cell and 100-200 uM in the syringe.

Q. Are there any improvements over ITC200 in terms of detection limit and noise profile?

The short term noise is improved and so the data looks better and gives confidence to the user when the signal is small. However the sample requirements are the same.

Q Is the cell a coin shape?

Yes, the cell shape and stiring mechanism were designed to maximize the response time of the instrument.

Q. How important is cell material?

Very important, you must make sure that cell material does not bind proteins or other biomolecules.

Q. How good do you think the system is for nanoparticle – protein interactions?

Yes, my colleague recently presented on the use of this instrument in the study of nanoparticles – you can play back the webinar here.

Q. Has the time it takes to equilibrate the cell to low and higher temps been improved?

No, but we believe this is very fast – a matter of minutes.

Q. Is the cell filling procedure improved?

There have been no changes to cell filling.

 

Software & Data Analysis Related Questions

Q. Will there be new software?

The software is completely new.

Q. Is the analysis software still Origin-based?

No, we believe however that all the functionality provided by Origin will be available to PEAQ users but it will be easier to use and to find the appropriate tools because of a ‘workflow’ approach to the software design.

Q. Does the software allow dissecting simultaneous enantiomer binding?

Yes

Q. Does the software allow analysis competition experiments for inverse titrations?

Yes, if both small molecules are in the cell and the protein is in the syringe

Q. How does the software deal with artefact peak?

An artefact between peaks can be isolated from the fitting and baseline drawing. It can also be ‘drawn around’ using a mouse controlled tool.

Q. Did you include peak-shape analysis (as known from NITPIC) for improved integration of peaks?

We do include an algorithm to predict where the peak ends and the baseline begins.

Q. Is it possible to analyze data obtained in VP-ITC with the new software?

It is possible but this has not been fully tested for all revisions and as such the software is not commercially available as a ‘stand alone.’

Q. Is the automatic analysis completely automatic?

Yes- completely automatic

Q. Is the automated data analysis for binding reactions only or does it also work for enzymatic reactions?

The enzyme analysis is improved but it is not fully automated.

Q. Can I still get Final Figure format?

Yes – with and without baseline removed.

Q. Can the experimental design tool be used for designing complex or multisite binding?

Yes- the design tool works for all the binding models we provide.

Q. What models are included into new analysis software?

All the previous models are supported- 1 site, 2 site, sequential, competition, dissociation and enzyme kinetics.

Q. Two-site analysis model was always the most “demanding” and hard to work with. Any improvement?

Yes- this is more likely to converge on the data and will be caught less frequently in a local minima.

Q. Are there novelties in the way that baseline fitting is performed & does the software include several options at this level?

Yes, it is difficult to discuss in general terms because this has changed gradually over the years. However I can tell you that the baseline is fit globally to the entire data set. The automated analysis uses a standard approach but this can be over ridden by the user using a number of tools provided with the software.

Q. How does data triaging work?

The software identifies data properties that are indicative of binding events or data quality-such as signal size or the time taken between injections.

Q. Is it possible to re-work manually the baseline if there are outliers?

Yes, the ‘rework’ tools have been made easier to use. For instance the entire isotherm can be visualized will working on one peak. Also, the integration markers and baseline markers can now be separated. This has the advantage that spurious peaks can be eliminated all together from the analysis process.

Q. How does the software normalise the ligand concentration?

If the customer so wishes, the data can be fitted using a fixed stoichiometry and either the cell or syringe concentration can be floated instead.

Q. Can you perform a global fit on repeated experiments (running the same titration three times, then fitting everything together).

No, this is not possible.

Q. Are you aware of the Affinimeter software, and how does it compare to your new analysis software?

Yes, we are aware of Affinimeter software. I believe that Affinimeter provide a wider range of fitting options. Our software is designed to make the more common data types easier to analyze.

 

General Questions

Q. What happened to the auto-ITC?

We now have the PEAQ-ITC Automated. This has some new functionality and some great new analysis software. The new functionality includes the ability to perform multiple experiments without refilling or cleaning the syringe. This was a request by some of our drug discovery customers who like to use the calorimeter to perform quick yes/no binding experiments for screening hits.

Q. Are you going to demo the new instrument?

Yes, the instrument is available for demo. Please contact your local representative or click here to request a demo.

Q. What are your plans for the future? Which improvements will the next generation of PEAQ instruments cover?

We will listen to our customers for feedback and strive for continuous improvement.