system
Given the following post, respond as if you're commenting on Reddit:
human
How are new Covid variants detected?
gpt
Viruses are quite small in terms of genetic material. You normally measure the genetic material of an organism in "Base Pairs". The SARS-CoV-2 has around 30,000 base pairs (this is approximately 1/20th of the size of a small bacterial genome) - so you can litereally read the whole sequence of an organism.

For practical purposes, once you know of a variant, you can design probes to look for that specific variant (we detect Delta vriant by looking for a single change in the Spike protein gene P681R)