The calcium assay is an important tool used in research. It is used to measure calcium levels in cell cultures. BD(tm) Calcium Assay Kits are available to measure calcium levels. They also include GECIs, synthetic indicators, and a multimode plate reader. Read on to learn more about these tools.

BD ™ Calcium Assay kit

The BD(tm) Calcium Assay kit is designed to conduct high-throughput screening of calcium levels in cells. The proprietary formulation enables a one-step, homogenous measurement of intracellular calcium levels. It also contains a non-fluorescent calcium indicator that becomes activated within the cell upon calcium binding. These dyes are pumped out of cells by organic anion transporters.


The GECI reporter element can be a single fluorescent protein or a FRET donor-acceptor FP pair. Single-FP GECIs typically consist of circularly permuted or split FPs that are modulated by changes in the recognition element. Two-FP GECIs contain two fluorescent proteins that are modulated by conformational changes of the recognition element. The resulting emission intensity of the donor and acceptor changes accordingly.

Synthetic Indicators

Intracellular calcium measurement is a critical component of many high-throughput assays in modern drug discovery. Synthetic calcium indicators have become a gold standard in this field because of their high reliability, high sensitivity, wide dynamic range, and spectral properties. However, genetically encoded calcium indicators (GECIs) are emerging as a viable alternative to synthetic calcium indicators, as they display stable expression and can compete with synthetic indicators in many applications.

CLARIOstar Plus Multi-Mode Plate Reader

The CLARIOstar Plus multi-mode calcium microplate reader combines flexibility with exceptional sensitivity, making it the perfect tool for research, assay development, and cell-based assays. It features highly sensitive filters, patented LVF Monochromators(tm), and a rapid full-plate autofocus. All of these features make detection and optimisation much easier.

The CLARIOstar Plus features LVF monochromators, which provide more sensitivity when working in fluorescence or luminescence mode. These filters incorporate linear variable filters and dichroic mirrors, allowing them to continuously adjust the wavelengths and bandwidths of the light coming from the sample.


Intracellular calcium measurement is a core component of life sciences research and is essential to many high-throughput assays used in modern drug discovery. Synthetic calcium indicators have become an industry standard for this purpose due to their ease of use, high reliability, wide dynamic range, and variety of spectral properties. However, genetically encoded calcium indicators (GECIs) have recently been developed and have proven superior to synthetic indicators in several applications. One of these is their stable expression.