Fig 1.

Typical amplification curves generated by Reactions ‘A’ and ‘B’ with dilution series of Delta variant RNA. A ten-fold dilution series of viral isolate Delta #02510 RNA covering the range 1:1000 to 1:1,000,000 was amplified by Reaction ‘A’ and Reaction ‘B’. Reaction ‘B’ generated the four curves on the left with Ct values of 20.5, 24.0, 27.6 and 30.9. In contrast, Reaction ‘A’ only just detected the lowest 1:1000 dilution with a Ct value of 39.3 (the very small curve on the extreme right). The three higher dilutions were undetected by Reaction ‘A’..