ELISA are immunoassays widely used in biomarker detection and validation. They have been used in research and clinical settings for more than 40 years, and they allow to quantify, in a simple way, thousands of biomarkers. New ELISAs are being developed every day, either for new biomarkers or new species. They can also be used to detect contaminants in food, water or industrial processes.
Technology-wise, there are several types of ELISAs, depending on whether they are based on double (or sandwich) antibody detection, direct detection, competitive detection, etc. It is not the scope of this post to enter into details about the different formats that an ELISA can have, but if you think that you need this info, feel free to suggest that I do a post on that!
Nevertheless, the aim of this post is to give some hints on how to reach the best result for your ELISA tests, based on some troubleshooting experience with researchers and clinicians all over Europe.