[The true error and the attributed error: analysis of the causes and remedies from specimen collection to response].

After a brief definition of accidental, systematic error and blunder, the AA. analyse the causes and remedies of the error, before and during the laboratory stage. During the latter they analyse the manual and automatic steps of the tests. The AA. conclude that the modern laboratory is a very efficient and sometimes resolving means in order to formulate a diagnosis. It's not the diagnosis.