An Italian court today refused to dismiss charges against the couple accused of murdering British student Meredith Kercher.
Lawyers for American Amanda Knox and her former boyfriend Raffaele Sollecito had challenged key DNA findings in the case.
Both were in court as the trial resumed after a summer break.
They are accused of murdering Miss Kercher, 21, from Coulsdon, Surrey, during a sex game at the apartment she shared in Perguia in November 2007. They deny the charges.
Defence lawyers said that some of the documents for DNA samples that prosecutors say link the defendants to the case were not made available to them early enough in the case.
But Judge Giancarlo Massei rejected the request and ruled that proceedings should continue.
Knox's DNA was found on the handle of a knife that might have been used in the murder, while Miss Kercher's DNA was found on the blade. The knife was found at Sollecito's apartment.
Knox's lawyer Carlo Dalla Vedova also argued the DNA traces allegedly belonging to Miss Kercher on the knife's blade were "too low" to be attributed with certainty.
Italian prosecutors say forensics and DNA experts have followed correct procedures while submitting the results of DNA tests to the court.
Both defendants were escorted in court today by police guards. Knox smiled to lawyers and family members as she walked in.
A third person, Rudy Hermann Guede of the Ivory Coast, was convicted in a separate trial last year and sentenced to 30 years.