Guru Gobind Singh Indraprastha University 1 article published in JoVE Biology Determination of Tripartite Interaction between Two Monomers of a MADS-box Transcription Factor and a Calcium Sensor Protein by BiFC-FRET-FLIM Assay Neelima Boora*1, Vibha Verma*1, Ridhi Khurana1, Gautam Gawande1, Sanchi Bhimrajka1, Komal Chaprana1, Meenu Kapoor2, Sanjay Kapoor1 1Interdisciplinary Centre for Plant Genomics, Department of Plant Molecular Biology, University of Delhi South Campus, 2University School of Biotechnology, Guru Gobind Singh Indraprastha University Here we present, a method to visualize ternary complex formation between three protein partners using fluorescent-tagged proteins by BiFC based FRET-FLIM assay. This method is valuable for studying protein-protein interaction complexes in vivo.