No Isolates

From the horse's mouth:

Since no quantified virus isolates of the 2019-nCoV were available for CDC use at the time the test was developed and this study conducted, assays designed for detection of the 2019-nCoV RNA were tested with characterized stocks of in vitro transcribed full length RNA...spiked into a diluent consisting of a suspension of human A549 cells and viral transport medium (VTM) to mimic clinical specimen1

The following clip, taken from the NBC Nightly News broadcast (Jan 24 2021), features Dr Wu Zinyou from the Chinese CDC, who confirms the virus was never isolated. The interviewer does not bat an eye at his statement.

The full segment can be found here and here