We offer a competitive Enzyme-linked Immunosorbent Assay (ELISA) that can detect Paralytic Shellfish Poisoning toxins in samples. PSP toxins contaminate shellfish across the globe and can have debilitating effects on human health (1). Our antibody binds saxitoxin and neo-saxitoxin with approximately equivalent affinity, and it can also detect GTX 1/4 and GTX 2/3 with an additional conversion step (2). As such, our ELISA is able to detect the most toxic versions of PSP toxins with limited cross-reactivity with nontoxic versions (2).