How to Install MDL Chime Manually in Firefox on Windows
A document for Protein Explorer (PE).

MDL Chime is the browser plugin that displays macromolecular structure, and is required for operation of Protein Explorer. See What Is Chime?.

Manual installation of MDL Chime is needed for Firefox on Windows. The MDL Chime installer works automatically in Windows with Internet Explorer, but that browser is not fully compatible with Protein Explorer. See Protein Explorer-Compatible Browsers.

  1. You will need to close Firefox during the installation, so you may wish to print this page now.

  2. If you don't already have Firefox, download and install it from If you already have it, it is a good idea to update it (Help, Check for Updates).

  3. Download the MDL Chime installer, and install Chime in Internet Explorer. Here are step by step instructions. (This creates the file npchime.dll needed below.)

  4. Copy the file npchime.dll
    (The other three "chime" files in the plugins directory are unnecessary: chime.html is the Chime release notes; chime26.isu and ChimeShim.dll are obsolete.)

  5. Close all Firefox browser windows. This is necessary since browsers load new plugins only when starting.

  6. Start Firefox. If you are on-line, clicking ATP should display a wireframe rendering of an ATP molecule (see image to the right). Here is another Chime test site. If these don't work, please see troubleshooting.

  7. Return to (or your downloaded copy of Protein Explorer) and Protein Explorer should now work.

Feedback to Eric Martz.