Mixed mode binding model development (CaptoMMC)

Dear CADET team,

I am currently trying to simulate and compare elution curves from mixed-mode chromatography (CaptoMMC) with an established CaptoMMC model in GoSilico. I understand that previous posts on the forum have suggested that CaptoMMC can be modelled well in some cases with GIEX. However, one of our components in GoSilico model requires the hydrophobic parameters n (stoichiometric factor) and S (steric hinderance factor) described by Nfor (2010) “High-throughput isotherm determination and thermodynamic modeling of protein adsorption on mixed mode adsorbents” for good mixed mode modelling. I am trying to discern if it is possible to account for this in CADET at this time. Perhaps someone has developed a non-official binding model? Or is mixed mode modelling coming in the future from the CADET team?

Many thanks.


Hey Ben and welcome to the forum,

I can’t make any promises about getting an MMC isotherm in CADET, but I’ll have a look. It would be a great help if you could send me a set of parameter values (including units) for the Nfor isotherm that I can use during testing to ensure the isotherm works.


Hey Ben,

it didn’t leave my mind and so I took the time and added the Nfor Isotherm to CADET Core here. There’s windows binaries in a comment of that PR. If you are on Linux, the build guide is in the documentation.

Because adding a binding model to CADET-Process is another step, for now I’d ask you to please use the old CADET-Python interface, as in this example I’ve prepared for the Nfor MMC isotherm.

When plugging in your parameters, be aware that GoSilico uses mol / L and CADET uses mol / m³ and some parameters will need to be transformed.

Getting parameters for our tests would still be very useful.



Hi Ron, thank you for your efforts looking into this isotherm. It’s much appreciated. I am looking at simulations using this binding model and will get back to you with questions soon but in the meantime, here are the parameters for the Albumin component as requested. I’ve added some info regarding resin porosity and ligand density if that helps too.

ALB parameters CADET.xlsx (10.9 KB)

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Hi Ben,

I kindly refer you to my paper on evaluating a series of stoichiometric isotherms for multimodal cation and anion exchange (MMC and Adhere).


The long short is that you don’t need the Nfor model (called Ottens Ext in my paper). From my experience, it is not any more useful than the GIEX and sometimes even worse. The GIEX is available in CADET and the k_{a, salt} term will take care of the hydrophobic interactions. In my paper I call it the extended SMA model but it is basically the same as GIEX.

It should be noted that I used ChromX in the referenced paper. I have another publication in press that expands on the work for Capto MMC and uses CADET. So I can confirm the GIEX works for multimodal in both softwares.