"There were no DNA hits in CODIS," the Pima County Sheriff's Department said on Tuesday, referring to the national Combined DNA Index System.
"At this point, there have been no confirmed CODIS matches in this investigation," the department said, suggesting that other DNA samples had been put through the system.
CODIS is a valuable storehouse of DNA taken from crime suspects or people with convictions. Any hits could identify possible suspects in Guthrie's disappearance.
The 84-year-old mother of NBC Today co-anchor Savannah Guthrie was reported missing from her Tucson-area home on February 1 after spending the previous night with family, police said.
Her blood was detected on the porch.
A porch camera recorded video of a man with a backpack who was wearing a ski mask, long pants, a jacket and gloves.
Gloves were found approximately three kilometres from Guthrie's home. The FBI has said that the gloves appeared to match those worn by the man in the video.
"There is additional DNA evidence that was found at the residence, and that is also being analysed," the sheriff's department said.
In addition, the department said investigators are working with a manufacturer and experts to try to locate Guthrie by detecting her heart pacemaker. News media reported that a "signal sniffer" device has been attached to low-flying aircraft.
Savannah Guthrie posted an Instagram video Sunday in which she issued an appeal to anyone with information about what happened to her mother.
"It is never too late to do the right thing," she said.
"And we are here. And we believe in the essential goodness of every human being, that it's never too late."
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