title: Protein chip for the parallel quantification of high and low abundant biomarkers for sepsis.
abstract: We present herein a protein chip for diagnosis of sepsis that combines both a sandwich and a binding inhibition format in order to quantify high (CRP) and low abundant proteins (cytokines, PCT, neopterin) in parallel. Using the combined assay format the lowest detectable concentrations for CRP, IL-6, IL-8, IL-10, TNFα, PCT, and neopterin are 3 mg/L, 15 ng/L, 26 ng/L, 65 ng/L, 40 ng/L, 78 ng/L, and 0.46 μg/L. Four different combined assay formats are tested, using separate or joint incubation steps of analytes and detection antibodies. Yet, low limit of detection (LOD) and short processing time are contradictory: while the combined assay performed in a multistep protocol is extremely sensitive (e.g., the LOD for IL-6 is 15 ng/L), but more time-consuming (4 h), the all-in-one protocol takes only 2.5 h, but suffers from lower sensitivity compared with the multistep protocol (e.g., the LOD for IL-6 is up to 40 times enhanced). Reproducibility is good in both cases (CV 5-20%).
authors.affiliation: AIT Austrian Institute of Technology, Health & Environment Department, Bioresources, Konrad Lorenz Straße 24, 3430 Tulln, Austria.
authors.forename: Ursula
authors.initials: U
authors.lastname: Sauer
authors.forename: Patrick
authors.initials: P
authors.lastname: Domnanich
authors.forename: Claudia
authors.initials: C
authors.lastname: Preininger
mesh_terms: D015415:Biomarkers / Q000032:analysis; D002097:C-Reactive Protein / Q000032:analysis*; D002116:Calcitonin / Q000032:analysis; D016207:Cytokines / Q000032:analysis; D005453:Fluorescence; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D019798:Neopterin / Q000032:analysis; D040081:Protein Array Analysis / Q000379:methods*; D011498:Protein Precursors / Q000032:analysis; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000175:diagnosis*; D019809:Streptavidin / Q000737:chemistry
chemical_list: D015415:Biomarkers; D016207:Cytokines; D011498:Protein Precursors; D011933:Reagent Kits, Diagnostic; D019798:Neopterin; D002116:Calcitonin; D002097:C-Reactive Protein; D019809:Streptavidin