For example, many proteins and cell membranes are liquid crystals. Other well-known examples of liquid crystals are solutions of soap and various related detergents, as well as the tobacco mosaic virus, and some clays.

As these cells grew and reached maturity, investigators exposed the retinal organoids to the SARS-CoV-2 virus. To their surprise, Menuchin-Lasowski et al. found that SARS-CoV-2 not only infected cells but also replicated. This was evident by the production of viral plaques in the cells that were exposed to the virus. The amount of viral plaque significantly increased within the first 24 hours and nearly doubled after another 24 hours. Interestingly, after 72 hours, the amount of plaque decreased back to the levels detected during the first 24 hour time point. Previous studies have observed a similar pattern of Covid-19 infection in human brain organoids.