IC ITC
description - what is IC ITC?
IC ITC ("I see ITC") and I2CITC ("I too see ITC") are software for analysing isothermal titration calorimetry (ITC) data. IC ITC was developed at The University of Sheffield in the group of Ihtshamul Haq. The auxiliary program prep4icitc and I2CITC (the windows-based successor of ICITC) were written at Cardiff University in the group of Niklaas J. Buurma. The core of the software package is a program capable of analysing complicated sets of equilibria (Figs. 1 & 2). A detailed description of IC-ITC can be found in: Buurma, N.J.; Haq, I. Methods 2007, 42, 162-172 (DOI: 10.1016/j.ymeth.2007.01.010) & Buurma N.J.; Haq, I. J. Mol. Biol. 2008, 381, 607-621 (DOI: 10.1016/j.jmb.2008.05.073). IC ITC is compatible with the VPITC and ITC200 instruments (MicroCal / GEHealthcare) and also with the nanoITC (TAInstruments).


Fig. 1: Set of equilibria (excluding ligand-competitor equilibria which are available as well) which were included in the standard version of IC ITC as of September 2008. Variables have been labeled as they are in the papers (vide supra) describing IC ITC and in the programme itself (note that the subscript on DNA-ligandnA1+nA2 has been corrected compared to the original supplementary information).

Current development of IC ITC
New equilibrium equations are being added to the program. Equilibria can also be added in collaboration, but at the programmer's discretion. The programs icitc and prep4icitc are being rewritten and combined into one stand-alone application for analysis of isothermal titration calorimetry data.


Fig. 2: Set of equilibria (as above) included in the beta version of IC ITC. Variables have been labeled as they are in the papers describing IC ITC and in the programme itself. Definitions for Variables for interaction with a competing host for the ligand and variables for micellisation (or cooperative aggregation) to be published. Concentrations of all species are given in blue and formatted as in the output of icitic.exe

Natural work flow
The work flow in ic itc is ordered around the natural sequence of data analysis steps as discussed in 10.1016/j.ymeth.2007.01.010. The core programme IC ITC (icitc.exe) or its successor I2CITC is used in combination with prep4icitc, where prep4icitc provides the graphical user interface for most aspects of data handling. Prep4icitc is used to generate the input files for ICITC and I2CITC in a user friendly way. Actual fitting then occurs using icitc.exe or i2citc_32.exe. Prep4icitc also facilitates post-fitting error analysis (Fig. 3).

prep4icitcIC ITCprep4icitc
data preparationdata analysiserror evaluation

Fig. 3: The IC ITC package

Programmes constituting the IC ITC package
ic_itc core of the programme. description
prep4icitc Generates all input files for IC ITC, allows sequential titrations as described in the literature, runs post fitting error analysis. Prep4icitc is effectively the GUI for ICITC guided data analysis

How do I get my copy of IC ITC?
Request your copy of ICITC and I2CITC by filling in the registration form and sending a message to Niek Buurma (buurma@cardiff.ac.uk) with subject line 'IC ITC request'. You will then receive a reply directing you to the download location. By default, you will be provided with the most recent stable beta version, in combination with information on which models can be considered stable and which interaction models are currently under development.

How do I use my copy of IC ITC?
When you start using ICITC and/or I2CITC, you may need some further instructions. Feel absolutely free to contact me to ask for further support. Requests for further support ae exactly what drives the development of the program. Manuals and user guide
Manuals are available in the form of a guided data analysis using example data and the FAQ. These documents are under construction and feedback (buurma@cardiff.ac.uk) is greatly appreciated.