Chloroplasts are responsible for photosynthesis in plants and algae, and are composed of specific proteins and photosynthetic pigments, such as chlorophylls and carotenoids. When chlorophylls are exposed to adequate light, they emit a red autofluorescence. The quantity and quality of this autofluorescence are indicators of cell health and growth of the plant/alga; these indicators can also be used to determine biomass, agricultural yield, and environmental factors that affect plants/algae. Utilization of chlorophyll fluorescence to measure these parameters requires appropriate detection technologies, such as fluorescence imaging and spectrometric techniques. In addition to basic findings, these technologies contribute to research related to several global challenges, such as food security and environmental conservation. Furthermore, plants and algae produce carotenoids, which are high-value pigments used as additives in food, feed, and healthcare supplements. Similar to chlorophyll, several carotenoids emit clear fluorescence. Unfortunately, the predominant autofluorescence of their pigments occasionally becomes an encumbrance to observing other cellular molecules.

This Methods Collection invites articles on a variety of important and unique techniques for autofluorescence detection, imaging, and evaluation. Techniques to reduce interference from fluorescent pigments have important applications in evaluating other molecules. These technologies may contribute to the study of the above-mentioned global challenges and to the improvement of human health. Although the techniques in this collection would mostly focus on plants/algae, they may also involve other unique photosynthetic organisms such as symbiotic organisms (such as relationships between heterotrophic organisms and autotrophic algae). These symbiotic relationships play an important role in ecology and help us understand biological evolution.