It is possible to introduce an artificial electron acceptor into the light reaction, such as a dye that changes color when it is reduced. These are known as Hill reagents. These dyes permitted the finding of electron transport chains during photosynthesis. Dichlorophenolindophenol (DCPIP), an example of these dyes, is widely used by experimenters. DCPIP is a dark blue solution that becomes lighter as it is reduced. It provides experimenters with a simple visual test and easily observable light reaction. 
In another approach to studying photosynthesis, light-absorbing pigments such as chlorophyll can be extracted from chloroplasts. Like so many important biological systems in the cell, the photosynthetic system is ordered and compartmentalized in a system of membranes.