Duplicate negative control sera were obtained from the same sheep prior to infection.
Duplicate negative controls (no template cDNA) were also run with every experimental plate to assess specificity and to rule out contamination.
For each selected gene, triplicate sets of PCR reaction samples including the 18S controls, and duplicate negative controls (reaction samples without cDNA templates), were prepared and run in a 96-well plate.
A print is made from the duplicate negative.
The duplicate negative looked pretty good -- better than any existing copy, on video or film.
That's how you make the duplicate negative.
The next best after that is a duplicate negative, which is made from the fine-grain master.
His executive producer in Paris, Fumiko Takagi, learned that a French film lab called GTC possessed a duplicate negative -- one generation closer to the original.
In 2008 a nearly complete 16-millimeter duplicate negative was found in Buenos Aires, and a new "Metropolis" incorporating footage from that lost treasure was released in May.
The studio made a duplicate negative for the sound version, one that actually contained less visual information than the silent negative, because of the additional space on the 35-millimeter filmstrip taken up by the optical soundtrack.
