Yes, an element that has been added to the DOM can be selected and referenced.
Or, if you already had a reference to it that you used when you added it to the DOM, you can continue to use that reference after it has been added as well.
Using this example, you can see that you can both use a current reference to a newly created element, as well as make a new reference to it.
http://jsfiddle.net/Czuvx/
HTML:
<div id='button'>hover me</div>
jQuery:
$('#button').hover(function() {
$('#newElement').remove();
var $myNewElement = $('<div id="newElement">new Element</div>');
$('body').append($myNewElement);
$myNewElement.css({color:'red'});
},
function() {
// This function has completely different namespace
// from the one that created and inserted #newElement
// and I can get a reference to it just like any other element
var $newReferenceToElement = $('#newElement');
$newReferenceToElement.css({color:'blue'});
});