Chime is a plug-in for your web browser (i.e. Netscape) that allows you to view interactive 3-D images of molecules on web pages.  In order to see the image, your browser must have Chime installed.  If you do not see the DNA oligonucleotide to the right, go here to download Chime.  You will need to register first, and then follow the installation directions.  Chime if free to all users.

Chime allows the viewer to manipulate the appearance of the image on the screen.  Click and drag the molecule at right to rotate the image.  Shift-click and drag up and down to zoom in and out.  If you right-click (or, for Mac users, hold down the mouse for a bit), you will get some menu options to control the appearance of the image. 

The author of a web page can embed Chime commands within the page to control the image appearance for the viewer. The World Index of Molecular Visualization has the most comprehensive list of Chime pages, with links to all sorts of useful Chime information.

Chime creates an image from a data file which identifies each atom of the molecule and gives its x, y, and z coordinates in three dimensional space.  The data files are identified by their extensions.  Chime recognizes a several different file formats, but pdb and mol files are the most common.  All mol files show double bonds explicitly whereas most pdb files won't.    Click here if you want to see the pdb file for the DNA molecule. 

Our next task will be to find files on the internet.