Elevated temperature and time abuse of harvested fish accelerate the growth of microorganisms normally present in the fish, increasing the breakdown of histidine to histamine. Human scombroid poisoning is caused from consuming fish with high levels of histamine. Scombroid poisoning has resulted in human mortality. Histamine production is common in fish such as tuna, mahi-mahi, bluefish, mackerel, anchovies and sardines. Also, it is produced in menhaden, a fish commonly used in the production of fish meal, which is a major protein supplement in animal feeds.
Histamine is extracted from a sample using a quick water extraction process.
After a wash step, substrate is added which reacts with the bound enzyme conjugate to produce blue color. More blue color means less histamine. The test is read in a microwell reader to yield optical densities. The control optical densities are used to form the standard curve and the sample optical densities are plotted against the curve to calculate the exact concentration of histamine. The test takes 20 minutes to perform and will provide results for up to 38 samples.