Referring to the liquid samples, identify the two samples that serve as controls for background auto-fluorescence. What are the potential source(s) of auto-fluorescence in each sample？Auto-fluorescence in this situation is fluorescence that is not due directly to rGFP.

The V sample and the water sample are two control sample for background auto-fluorescence. Some credible sources of auto-fluorescence in the V strain could be the mitochondria in each of the cells which enables the cells to fluoresce when excited. Usually when there are increased numbers of tyrosine, tryptophan and phenylalanine, the structures can fluoresce despite not having any GFP protein.

Explanation:

Background fluorescence is the fluorescent signal that is seen but not wanted. Background fluorescence comes from a various sources. There are many different ways that experimental design contributes to background fluorescence, you likely have multiple options to reduce it. V-sample and water sample are used to control auto-fluorescence.