In the course of an immune response, reactive oxygen species (ROS) are produced and released during a respiratory burst in order to damage pathogens. ROS can be measured using Pholasin®, the photoprotein of the marine rockboring bioluminescent mollusk. The protein glows upon activation by free radicals and is used in the ABEL® Antioxidant kit.
The kit was used in combination with a luminescence-capable BMG LABTECH plate reader to determine stimulation of leukocytes in whole blood. Blood samples were stimulated with either the tetrapeptide fMLP or with phorbol 12-myristate 13-acetate (PMA). Upon addition of the stimulant by on-board reagent injectors, ROS response was monitored. Differences in ROS-production upon fMLP and PMA were detected. The monitoring of leukocytes over hours was enabled by the temperature control integrated in the reader.