On Jul. 22, 2021, Twist Bioscience announced that it had started shipping its synthetic RNA reference controls for the SARS-CoV-2 Delta (B.1.617.2) and B.1.617.3 variants first identified in India and spreading rapidly worldwide.

In March 2020, Twist launched its first synthetic SARS-CoV-2 RNA distinct reference sequences as positive controls for the development of both next-generation sequencing (NGS) and reverse transcription-polymerase chain reaction (RT-PCR) assays to test for SRS-CoV-2.