lester >> gabe gutierrez starting us from new york across the country this evening medical detectives are searching for the new variant, analyzing positive covid tests in dozens of labs. erin mclaughlin got access to one of them in san diego. >> reporter: tonight, the cdc and scientists at nearly 70 state and local health labs are on the hunt for omicron, sequencing 40,000 to 80,000 specimens each week. >> given what we have seen in southern africa and certainly in europe, we do expect that it is here. >> reporter: like all viruses, covid mutates. that's normal. but what has experts concerned is the high number of mutations in the omicron variant, which attaches to human cells, making it more transmissible to others we were invited inside the labs at uc san diego where scientists are sequencing positive covid tests to check for the mutated virus. >> we get a lot of delta right now. it is pretty much everything that we