title: A sensitive sandwich ELISA to measure (1→3)-β-d-glucan levels in blood.
abstract: A highly sensitive (1→3)-β-d-glucan (β-glucan)-specific sandwich ELISA was developed using a fragment of recombinant horseshoe crab factor G protein. The factor G fragment, which was expressed in Escherichia coli, contains a QQWS motif, two β-glucan-binding domains, and an additional N-terminal cysteine residue. The sensitivity of our ELISA was comparable to a conventional (1→3)-β-d-glucan detection method using a horseshoe crab-clotting reaction such as an amebocyte lysate-based assay. In addition, the β-glucan levels measured by our sandwich ELISA in plasma samples showed a good correlation with those measured by the amebocyte lysate-based assay. In the case of our sandwich ELISA, it is not necessary to pre-inactivate interfering substances in plasma samples that is essential for the conventional amebocyte lysate-based assay. Moreover, the assay time of the ELISA method is much shorter than that of the amebocyte lysate-based assay. Because of these advantages, the ELISA system will be more suitable for high-throughput analysis in clinical laboratories using general clinical auto-analyzers. β-glucan is a typical biomarker for fungal infections and the measurements of β-glucan levels by our ELISA could be useful for the diagnosis of fungal infections.
authors.affiliation: Genome Research Laboratories, Wako Pure Chemical Industries Ltd., Amagasaki, Hyogo 661-0963, Japan. yoneda.akito@wako-chem.co.jp
authors.forename: Akito
authors.initials: A
authors.lastname: Yoneda
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kurokawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001774:Blood Chemical Analysis / Q000379:methods / Q000706:statistics & numerical data; D001779:Blood Coagulation Factors / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods* / Q000706:statistics & numerical data; D006737:Horseshoe Crabs / Q000235:genetics; D006801:Humans; D037102:Lectins / Q000235:genetics; D008033:Limulus Test; D008969:Molecular Sequence Data; D009181:Mycoses / Q000097:blood / Q000175:diagnosis; D011485:Protein Binding; D011509:Proteoglycans; D011994:Recombinant Proteins / Q000235:genetics; D012680:Sensitivity and Specificity; D017386:Sequence Homology, Amino Acid; D047071:beta-Glucans / Q000097:blood*
chemical_list: D001779:Blood Coagulation Factors; D002352:Carrier Proteins; D017931:DNA Primers; D037102:Lectins; D011509:Proteoglycans; D011994:Recombinant Proteins; D047071:beta-Glucans; C037937:glucan-binding proteins; C010770:polysaccharide-K; C085383:coagulation factor G, horseshoe crab