Cyclic dinucleotides (CDNs) are ubiquitous cellular messengers that serve important signaling functions in all domains of life. To better understand CDN signaling systems in both eukaryotes and prokaryotes, Cayman, in conjunction with the expert nucleotide scientists at Biolog Life Science Institute, has developed competitive immunoassays for the specific detection of 2’3’-cGAMP, 3’3’-cGAMP, 3’2’-cGAMP, cyclic di-GMP, and cyclic di-AMP. These assay kits enable sensitive, accurate, reliable quantification of CDN levels in mammalian, bacterial, and insect samples.