SO fiddle

Test Fiddle mainly for SO Questions

by Nick Craver

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/overcast/jquery-ui.css">
<table>
<tr>
    <td class="sede_co.uk">Test</td>
</tr>
</table>

JavaScript

$("td.sede_co\\.uk").css('color', 'red');