In brief, BALB/c or NMRI mice (Charles River, Sulzfeld, Germany) were used at the age of 8 weeks. agglutinin (limit of detection 22 pg/mL for abrin; 35 pg/mL for agglutinin). Furthermore, an abrin-specific lateral circulation assay was developed for quick on-site detection (limit of detection ~1 ng/mL abrin). Assays were validated for complex food, environmental and clinical matrices illustrating broad applicability in different threat scenarios. Additionally, the antibodies turned out to be suitable for immuno-enrichment strategies in combination with mass spectrometry-based methods for AS8351 unambiguous identification. Finally, we were able to demonstrate for the first time how the developed assays can be applied to detect, identify and quantify abrin from a clinical sample derived from an attempted suicide case including belongs to the family and is also known as jequirity bean, crabs vision, rosary or paternoster pea herb. It can be found in many tropical and subtropical areas across the globe. The seeds AS8351 contain the AS8351 highly harmful lectin abrin, a member of the type II ribosomal inactivating proteins (RIPs) family. These cytotoxic lectins facilitate cell death by halting protein synthesis by depurinating a specific adenine in the sarcin-loop of the ribosomal RNA. Type II RIPs consist of a catalytically active A-chainthe RNA N-glycosidaseand a sugar-binding B-chainthe lectin partwhich mediates cellular binding and uptake [1]. A number of highly harmful herb proteins including ricin (castor oil herb, and [2,3,4]. Herb RIPs are thought to protect the generating organism against predators and fungi, whereas bacterial RIPs act as potent pathogenicity factors. Due to their high toxicity, RIPs are investigated in agriculture (pest control) or medicine (immunotoxins, anti-tumor and anti-viral activity) and some have also gained military or criminal interest [5,6,7,8]. Here, AS8351 ricin is the best-known example, but abrin has also been used with malevolent intention recently; consequently, both toxins are outlined as select brokers [9,10]. Several reports cover the use of abrin in attempted murders or in a biothreat scenario [11,12,13,14], and accidental or suicidal AS8351 poisonings with seeds have been reported [15]. Its lethality depends on the amount of seeds and the application route. Fatality after oral ingestion is usually rare in humans, while injection seems to be more severe [16,17,18,19,20,21,22,23]a characteristic that has been noted for ricin previously [24]. Toxicological data from animal studies indicate that this major toxin abrinas with other protein toxinsis more potent when applied systemically (half maximal lethal dose, LD50, in rats: 0.3C0.5 g/kg) compared to inhalation (rat LD50 3C4 g/kg) and least toxic via the oral route (mice LD50 2C3 mg/kg) [15,25]; however, the exact concentration and purity of the abrin used in those studies remain elusive. roots and leaves have been used in traditional (ayurvedic) medicinee.g., to treat coughingwhile the seeds can be laxative and abortive [7]. Moreover, boiled (detoxified) seeds can be part of the local diet in regions ZCYTOR7 where is usually common [7]. Cooking or baking is used for other legumes (seeds contain not only the harmful lectin abrin in four different isoforms (abrin-a, abrin-b, abrin-c, abrin-d), but also another highly related lectin named agglutinin (APA). While abrin is usually a canonical A-B toxin of 63C67 kDa, APA is usually a dimer (~ 134 kDa) of two non-covalently linked A-B molecules of 67 kDa each. It is worthy of note that APA is usually far less harmful compared to abrin but functions as a hemagglutinin [26,27]; consequently, APA is not considered a select agent. APAs and abrins subchains share >70% identity at amino acid level (Table 1), which makes discrimination between these two molecules challenging. Table 1 Amino acid-sequence identity of abrin compared to agglutinin and the related proteins ricin and.