this group continues to do great work with a control group cell line to show the problem with viral isolation processes.

This protocol demonstrated that the growth medium for cell cultures when reduced to very low nutrient levels causes many of the observed "viral" effects which we attribute to pathogens

they used 2% fetal bovine serum as the nutrient medium

https://controlstudies.substack.com/p/controls2?utm_campaign=email-half-post&r=4cnjta&utm_source=substack&utm_medium=email