Can I Take a Covid-19 Rapid Antigen Test on Shabbat?

Now that Covid-19 rapid antigen tests are widely available, can I take them on Shabbat? We've previously talked about the halakhic restrictions on medical therapeutics on Shabbat (Responsa Radio #21), do these restrictions extend to diagnostics? Are there challenges that arise from the mechanics of the test itself, such as erasing the control line or dying a new color on the test strip?