How to use alamarBlue®

alamarBlue® can be used in a wide range of scientific research areas and applications including experiments involving cell proliferation, cell viability, bioassays for relative cytotoxicity, cytokine assays, cell metabolism studies, drug susceptibility and toxicology studies.

Simple and easy work flow

Just add the ready-to-use alamarBlue® solution to the cells, incubate for at least 1-4 hours at 37°C between pH6.8 and pH7.4. Read the fluorescence or absorbance to measure cell respiration as an indicator for proliferation and cytotoxicity.

  • Continued growth maintains a reduced environment (fluorescent, red).
  • Inhibition of growth maintains an oxidized environment (non-fluorescent, blue). 
  • Absorbance is monitored at 570 nm and 600 nm.
  • Fluorescence is monitored at 530-560 nm excitation wavelength and 590 nm emission wavelength. 

alamarBlue has a simple and easy work flow

alamarBlue® reduction is regularly measured using absorbance, which gives good levels of accuracy for most experiments, and is particularly easy to use. In general more sensitive readings can be obtained using fluorescence, especially when attempting to measure very small changes in reduction. This is principally because there is little interference from unreduced alamarBlue® on the spectra of reduced alamarBlue® when measured by fluorescence. However, when measuring by absorption there can be considerable overlap of the oxidized and reduced forms of alamarBlue®.


alamarBlue® is manufactured for Bio-Rad by Trek Diagnostic System. U.S. patent 5,501,959.