Genetically encoded Ca2+ indicators: Properties and evaluation

Genetically encoded calcium ion (Ca2+) indicators have become very useful and widely used tools for Ca2+ imaging, not only in cellular models, but also in living organisms. However, the in vivo and in situ characterization of these indicators is tedious and time consuming, and it does not provide information regarding the suitability of an indicator for particular experimental environments. Thus, initial in vitro evaluation of these tools is typically performed to determine their properties. In this review, we examined the properties of dynamic range, affinity, selectivity, and kinetics for Ca2+ indicators. Commonly used strategies for evaluating these properties are presented. This article is part of a Special Issue entitled: 12th European Symposium on Calcium. (C) 2013 Elsevier B.V. All rights reserved.