Isoelfocus 3.0 (*)
A multimedia computer-aided learning program on Isoelectric Focusing and its derived techniques as tools in biomedecine and agrofood industries.
(  IDDN.FR.001.510016.R.C.1997.000.31235  )

PC and MAC version

Screen display of oral commentary.

Optional connexion to Web sites.

Authors : ** CADE-TREYER Denise; CADE Ambroise ; ***DARJO Alain ; JOUVION-MORENO Myrian
University Pierre & Marie CURIE 4, Place Jussieu 75 252 PARIS Cedex 05
**e-mail :
***e-mail :

(*)For users of the preceding version 1.0, see the remark on the new downloading process in 6.Updating.

  1. Introduction to isoelfocus and its fields of application

  2. Computer specification

  3. How to download and install isoelfocus

  4. How to run isoelfocus

  5. RFC (Request For Comments)

  6. Updating

  7. Link to other Web sites dedicated to electrophoresis

1. Introduction to isoelfocus and its fields of application :

Photo : IEF Photo : titration curves Photo : 2D eletrophoresisPhoto : capillary IEF

Isoelectric focusing (IEF) is the high resolution electrophoretic separation, in a pH gradient of charged amphoteric molecules, notably proteins. With its developments and derived techniques (2D-electrophoresis, Capillary IEF...) IEF has gained increasing importance, as a tool in many, biomedical and agrofood research and industrial fields. There is therefore a high demand for thorough theorical and practical understanding of the basics of IEF, not only for students’education, but also, for scientists, clinicians, engineers and technicians.

«Isoelfocus» is a multimedia interactive computer-aided learning program, which should be a stimulating approach of IEF, before to dive into more refined and exhaustive printed textbooks on the subject. With easy updating and customizing, it lends itself well to teaching.
At the heart of IEF methods lies the titration curve, which is the display of the charge behaviour, along a pH gradient, of a protein to be separated. The titration curve of each protein predicts its isoelectric point, which is the pH where the net charge of the protein is zero. Isoelfocus has thus implemented the titration curve as a comprehensive tool for IEF-based methods.

Some relevant examples will highlight the nowadays wide-spread use of IEF technologies :

Photo : IEF tests in biomedicine Photo : IEF tests in food industries Photo : IEF tests in agriculture

Hospital reference centers of drepanocytocis use IEF as a routine test for diagnosis of sickle-cell anemia, the most prevalent genetic disease in African regions rife with malaria (1% prevalence) and in some european or american highly urbanized regions with black ethnic groups (1/500 births).
IEF of glycosylated hemoglobin, a reliable indicator of blood sugar level, is currently used in clinical monitoring of diabetics.
In clinical genetics, IEF phenotyping of blood proteins (PGM1, transferrin etc.) is commonly used.
In biotechnology and pharmaceutical industries, IEF fingerprinting of monoclonal or recombinant antibodies is required for database registration or for release assays of diagnostic kits or of glycoforms of recombinant proteins as therapeutic products. Recent optimization has allowed capillary IEF to be validated, for these purposes, as an automated quantitative test.
In agrofood industries, IEF is one of the assays listed in FDA’s points to consider for protein quality control of foodstuffs and fraud surveillance for meat, fish, cheese, flour etc...from fresh to deepfrozen or canned products.
IEF tests are widely used for determination of cereal or vegetable varieties in agriculture or food processing industries, as required by law of most countries. At the international level, the CODEX (*) will doubtless be brought to recommend IEF for protein quality control and for variety determination.
Proteome research : 2D electrophoresis (IPG-dalt) has become the reproducible separation method of reference, coupled with mass-spectrometry or other analytical approaches and with web browser-based bioinformatic tools, for protein mapping, sequencing, database development and screening, taxonomic studies, molecular imaging and functional analysis, search for  clinical markers as well as for drug target design.

(*) The CODEX (or Codex Alimentarius) is the international agency created by FAO and WHO in 1962 to harmonize the legislation in food exchanges.WTO (the World Trade Organization) must comply with the standards recommended by the CODEX to give a ruling on matters of contention in agrofood exchanges between countries.


2. Computer specification :        

PC : 90 Mhz or faster PC ; at least 8Mb RAM ; hard disk : 50 Mb free for loading the files ; Monitor : configured to VGA (640 x 480) with 65000 colors ; sound card and speakers.
Windows 95 or later version.

MAC : hard disk : 50 Mb free for loading the files ; minimal multimedia configuration.

3. How to download and install isoelfocus :

Isoelfocus is distributed free of charge. Commercial use is not authorized. Users are under their own responsibility.
Isoelfocus is subdivided into several files for easy transfer.
Notice : in order to obtain an efficient transfer MS Internet Explorer should be used.

Preparing PC version

It is mandatory to first download the base file
  : basePC.exe.
You must save it in a temporary directory (for instance C:\temp).

Then create a folder (named for instance "Isoelfocus"), at the place of your choice, in which the self extracting basePC.exe will be decompressed.

Then click on the basePC.exe file in C:\temp to install its content into the created folder.

Preparing MAC version

First create a folder (named for instance "Isoelfocus"), at the place of your choice.

It is mandatory to download the Runa4m.hqx file and to expand it (with Stuffit Expander ). The resulting folder is "Authorware 4 components", from which you will have to transfer into the created Isoelfocus folder the Xtras folder and the Runtime for MAC (Runa4m.ppc for Power PC Mac or Runa4m.fat for any Mac).

You have to download the following files : !Cthbsea.bin and !Aapisea.bin. Then you must expand these files (with Stuffit Expander). The resulting video files (Cthb1.avi and Api256.avi) must be stored into the folder you have created ("Isoelfocus"). Notice that despite their name they have the MOV format. These names must be kept unchanged.

If necessary recent versions of Stuffit Expander can be downloaded at :

Downloading the Isoelfocus Modules on PC and MAC

The modules are encoded in files suitable for PC and MAC.

Notice that each file can be downloaded and installed separately with time and run independently. The module 11 has been subdivided into 3 files.

Click on each file you want to download on the list of modules below. You must save each of them into the folder you have just created ("Isoelfocus" for instance).

List of Modules File Ko Update
Module 1 Overview of the applications of IEF avprog1 4768 19/07/01
Module 2 The IEF Process prog001 2555 19/07/01
Module 3 The titration curve of a single protein prog003 1009 19/07/01
Module 4 The titration curve of a protein mixture prog004 1540 19/07/01
Module 5 The titration curve as a tool for protein purification postpr04 3871 19/07/01
Module 6 The resolving power in IEF resolut 1993 19/07/01
Module 7 The electric parameters prog007 2302 19/07/01
Module 8 Generation of the pH gradient gradient 2250 19/07/01
Module 9 The pH gradient drift gradrift 955 19/07/01
Module 10 Immobilized pH gradients (IPG) immobil 3070 19/07/01
Module 11 Preparative IEF (1) prepar 547 19/07/01
Module 11 Preparative IEF (2) prepar2 4418 19/07/01
Module 11 Preparative IEF (3) prepar3 767 19/07/01
Module 12 2D-Electrophoresis bidim 2516 19/07/01
Module 13 Capillary IEF capill 1906 19/07/019
Module 14 IEF Workshop workshop 631 19/07/01
Introduction - Preface intrelec 2114 19/07/01
Main Menu - Key Words - References routeur 164 19/07/01
PC Runtime
Attached Files (Video, Xtras...)
BASEPC.EXE 4309 07/06/99
MAC Runtime
Attached Files (Xtras)
runa4m.hqx 9076 04/08/97

4. How to run isoelfocus : 

Isoelfocus is displayed in a 640 X 480 window. So, for the best screen display, 640 X 480 resolution should be maintained.

First open the folder in which you have installed Isoelfocus.

On the list of directories and files displayed, it is mandatory to first double-click on the Runtime file (Runa4w32 for PC or Runa4m for MAC). A dialog box will then open and display the list of files (each file contains a module). On clicking on one of them you will run it.

Click on intrelec file  to run once isoelfocus from the beginning (with introduction and preface).

Routinely, on clicking on the routeur file you will display the main menu, wherefrom each module can be run. The main menu gives also access to the keyword index and to the references.

5. RFC (Request For Comments) :

Comments are welcome and may be addressed to the authors by e-mail :

  1. what defect could you point out :
    what improvement do you suggest :
    at the scientific level (S)
    at the didactic level (D)
    in running Isoelfocus (R)
  2. specify your suggestion to help customize Isoelfocus for your own teaching use
    - for academic students’education (A)
    - for training in industrial milieux (I)

6.  Updating

Isoelfocus is on the Web since march 1998. Thanks to numerous suggestions or responses to RFC, the present version for PC and MAC has been improved and especially enriched with historical, research and technical comments or hyperlinks. The structure of Isoelfocus has been changed : the Runtime is from now on outside each module. Therefore users of the version 1.0 must download de novo the   version 3.0 as a whole according to the process described in § 3. Users of the version 2.0 have only to download the files of the modules.

Further updates of the different modules will be displayed on this Web Page, on the table "list of modules" (column:update). You will have only to download an updated file to your Isoelfocus repertory. A revised module will automatically replace the previous version.

7. Link to other Web sites dedicated to electrophoresis : (French Electrophoresis and Proteomic Analysis Society)
(Swiss Electrophoresis Society) (British Electrophoresis Society) (American Electrophoresis Society) (Japenese Electrophoresis Society) (German Electrophoresis Society) (Nordic Separation Sciences Society) Electrophoresis Society) (Expasy Server with research tool for Web sites in Electrophoresis)

Isoelfocus was awarded the 1998 Amersham-Pharmacia Biotech Prize of Electrophoresis
at the Swiss and French Electrophoresis Societies joint Conference ( Basel 3 Dec 1998)

Isoelfocus obtained a Gold Award at the 1999 CERVOD (Concours d'Etudes et de Réalisations pour la Valorisation des Outils Didactiques) : French competition of studies and products designed to promote didactic tools.

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