The Online Medical Dictionary is a searchable dictionary of definitions from medicine, science and technology.
http://cancerweb.ncl.ac.uk/cgi-bin/omd?Z-DNA
Another English dialectal form is izzard or izzed /ˈɪzəd/, which dates from the mid-18th century and probably derives from the French et zède "and z". ...
http://en.wikipedia.org/wiki/Z
Offer Street maps, CD-Roms and digital maps for Great Britain. Company history and contact details.