Journal: The Analyst

Article Title: An electrochemical biosensor for rapid detection of anti-dsDNA antibodies in absolute scale.

doi: 10.1039/c8an00020d

Figure Lengend Snippet: Scheme 1. Detection strategy. Positive or negative serum samples (containing 1/80 fetal bovine serum plus either murine monoclonal anti-dsDNA [red] or irrelevant [green] antibodies) were incubated with dsDNA-modified carbon electrodes, washed, and later incubated with anti- mouse IgG antibodies conjugated to HRP enzyme [blue] (A). In a more time-efficient and automatization-compatible strategy, conjugated antibodies were mixed with the serum samples before incubation (one-step, B).

Article Snippet: D ow nl oa de d by T uf ts U ni ve rs ity o n 7/ 3/ 20 18 9 :0 7: 02 P M . monoclonal anti-dsDNA antibodies (α-dsDNA: sc-58749), normal mouse immunoglobulins (m 79 IgG: sc-2025) and mouse monoclonal anti-human CD9 (α-CD9: sc-13118) and anti-Cy3 (sc-80 166894) antibodies were purchased from Santa Cruz Biotechnology INC. Rabbit HRP-81 conjugated anti-mouse IgG (α-m-IgG/HRP, ab6728) was purchased from Abcam.

Techniques: Incubation, Modification

Journal: The Analyst

Article Title: An electrochemical biosensor for rapid detection of anti-dsDNA antibodies in absolute scale.

doi: 10.1039/c8an00020d

Figure Lengend Snippet: Figure 1. Specificity of α-dsDNA antibody by enzyme-linked immunosorbent assay. Plates were sensitized with vortexed (squares) or intact (circles) salmon sperm DNA and incubated with different concentrations of α-dsDNA antibody (black) or mouse IgGs as a control (white).

Article Snippet: D ow nl oa de d by T uf ts U ni ve rs ity o n 7/ 3/ 20 18 9 :0 7: 02 P M . monoclonal anti-dsDNA antibodies (α-dsDNA: sc-58749), normal mouse immunoglobulins (m 79 IgG: sc-2025) and mouse monoclonal anti-human CD9 (α-CD9: sc-13118) and anti-Cy3 (sc-80 166894) antibodies were purchased from Santa Cruz Biotechnology INC. Rabbit HRP-81 conjugated anti-mouse IgG (α-m-IgG/HRP, ab6728) was purchased from Abcam.

Techniques: Enzyme-linked Immunosorbent Assay, Incubation, Control

Journal: The Analyst

Article Title: An electrochemical biosensor for rapid detection of anti-dsDNA antibodies in absolute scale.

doi: 10.1039/c8an00020d

Figure Lengend Snippet: Figure 2. Electrode modification with dsDNA and electrochemical sensing of α-dsDNA antibodies. A) cyclic voltammograms showing guanine oxidation (arrow) in dsDNA-modified electrodes (solid line) vs buffer-treated (dashed line) screen-printed carbon electrodes. B) Intensity vs time curves for TMB reduction on the electrode surface at – 0.1 V. dsDNA- modified BSA-blocked electrodes were incubated with α-dsDNA antibodies at two different concentrations (solid lines), normal mouse IgG at 2.5 µg / mL (thick dashed line), or buffer (thin dashed line), and then incubated with α-mouse IgG/HRP conjugates, followed by addition of a TMB/H2O2 solution.

Article Snippet: D ow nl oa de d by T uf ts U ni ve rs ity o n 7/ 3/ 20 18 9 :0 7: 02 P M . monoclonal anti-dsDNA antibodies (α-dsDNA: sc-58749), normal mouse immunoglobulins (m 79 IgG: sc-2025) and mouse monoclonal anti-human CD9 (α-CD9: sc-13118) and anti-Cy3 (sc-80 166894) antibodies were purchased from Santa Cruz Biotechnology INC. Rabbit HRP-81 conjugated anti-mouse IgG (α-m-IgG/HRP, ab6728) was purchased from Abcam.

Techniques: Modification, Incubation

Journal: The Analyst

Article Title: An electrochemical biosensor for rapid detection of anti-dsDNA antibodies in absolute scale.

doi: 10.1039/c8an00020d

Figure Lengend Snippet: Figure 3. Optical and electrochemical response of the sensor. A) Absorbance changes as a function of the concentration of m α-dsDNA (black circles) or mouse IgGs (open circles). B) Reduction current of TMB at 100s as function of the concentration of α-dsDNA (black circles) or mouse IgGs (open circles). LOD (limit of detection) was determined as the background signal plus three standard deviations. For visualization purposes, the current axis direction was inverted. Error bars correspond to the standard error of the mean of two independent replicates. Bi-electrodes containing specific and irrelevant antibodies at the same concentration were assayed in parallel.

Article Snippet: D ow nl oa de d by T uf ts U ni ve rs ity o n 7/ 3/ 20 18 9 :0 7: 02 P M . monoclonal anti-dsDNA antibodies (α-dsDNA: sc-58749), normal mouse immunoglobulins (m 79 IgG: sc-2025) and mouse monoclonal anti-human CD9 (α-CD9: sc-13118) and anti-Cy3 (sc-80 166894) antibodies were purchased from Santa Cruz Biotechnology INC. Rabbit HRP-81 conjugated anti-mouse IgG (α-m-IgG/HRP, ab6728) was purchased from Abcam.

Techniques: Concentration Assay

Journal: The Analyst

Article Title: An electrochemical biosensor for rapid detection of anti-dsDNA antibodies in absolute scale.

doi: 10.1039/c8an00020d

Figure Lengend Snippet: Figure 4. “One-step” vs “two-step” method. Reduction current recorder at 100s after incubation with serum samples containing either relevant or irrelevant antibodies at the same concentration with the “two-step” (A) or “one-step” (B) method. To reduce batch effects, specific (black circles) and irrelevant (mouse IgG: open circles; monoclonal α-human CD9, open triangles) antibody-containing samples were incubated in parallel in bi-electrode strips. Diamonds correspond to carbon electrodes not modified with dsDNA (negative controls). Error bars correspond to the standard error of the mean. Student t test (two-tailed) was carried out to test statistically significance in the difference between positives and negatives. The current corresponding to the detection limit of the method was used as cut-off in order to establish assay specificity and sensitivity. Alternatively, a mobile cut-off was used in order to obtain ROC (receiving operating characteristic) curves for both methods (C).

Article Snippet: D ow nl oa de d by T uf ts U ni ve rs ity o n 7/ 3/ 20 18 9 :0 7: 02 P M . monoclonal anti-dsDNA antibodies (α-dsDNA: sc-58749), normal mouse immunoglobulins (m 79 IgG: sc-2025) and mouse monoclonal anti-human CD9 (α-CD9: sc-13118) and anti-Cy3 (sc-80 166894) antibodies were purchased from Santa Cruz Biotechnology INC. Rabbit HRP-81 conjugated anti-mouse IgG (α-m-IgG/HRP, ab6728) was purchased from Abcam.

Techniques: Incubation, Concentration Assay, Modification, Two Tailed Test