Drug accumulation thickens cell membrane
An image gallery of wildtype BY4716 yeast cells treated with 25µM amiodarone for 45 minutes. Amiodarone, a cationic amphipath (fat-soluble weak base), is known to cause phospholipidosis in lab animals chronically treated it.
Here, amiodarone-treated yeast cells accumulated the drug in vacuolar membrane, causing cup formation. Bilayer expansion is evident at the concavities as white stretches in the membrane.