Part 1: Calcium
Intracellular calcium is related to many different physiological processes like neurotransmitters release, muscle contraction, ion channel gating, second messenger pathways, etc. For this reason, calcium quantification is performed in a variety of cellular studies to highlight molecular mechanism involved in different process.
Measuring intracellular calcium can be done using different techniques: the use of fluorescent indicators has become the most popular. Depending on their nature, they can be classified as Fluorescent Dyes (Fluo-4, Fura-2, calcium green, etc.) or Fluorescent Proteins (aequorin, derivatives of the green fluorescence protein (GFP) such as yellow camaleons, etc.). The main difference between them is the fact that fluorescent proteins can be easily targeted to different cell compartments while most dyes cannot.