Phospho-tau217, Phospho-tau181, and Phospho-tau231 (p-tau217/181/231) Full length Protein (Recombinant protein)

1. Validation of High-Specificity of anti-p-Tau217/181/231 antibodies with p-Tau217/181/231 peptides

ELISA validation data confirm the high specificity of the anti-p-Tau217, p-Tau181, and p-Tau231 antibodies.

Method (Direct ELISA): ELISA plates were individually coated with p-Tau217, p-Tau181, and p-Tau231 peptides. Following a blocking step, the plates were incubated with serially diluted primary antibodies (anti-p-Tau217, anti-p-Tau181, anti-p-Tau231, or anti-total-Tau). Bound antibodies were detected using HRP-conjugated secondary antibodies, and colorimetric quantification was performed with TMB substrate, measuring absorbance at 450 nm.

Result: The anti-p-Tau217 antibody selectively binds to the p-Tau217 peptide (Figure A), while the anti-p-Tau181 antibody exclusively recognizes the p-Tau181 peptide (Figure B). Similarly, the anti-p-Tau231 antibody demonstrates specific binding to the p-Tau231 peptide (Figure C). In contrast, the anti-total-Tau antibody shows no cross-reactivity with p-Tau217, p-Tau181, or p-Tau231 peptides (Figure D). These results confirm the excellent specificity of the antibodies.

Click to Zoom

Fig1. High specificity and reliability of anti-p-Tau217/181/231 antibodies in ELISA.
A. anti-p-Tau217 antibody binds specifically to p-Tau217 peptide.
B. anti-p-Tau181 antibody binds specifically to p-Tau181 peptide.
C. anti-p-Tau231 antibody binds specifically to p-Tau231 peptide.
D. anti-Total-Tau antibodies don't recognize p-Tau217/181/231 peptides.

2. High specificity and reliability of pTau217/181/231 Phosphorylated full-length protein

GeneMedi provides high-quality pTau217, pTau181, and pTau231 full-length protein with well-characterized specificity.
Method (Direct ELISA): Phosphorylated full-length proteins p-Tau217, p-Tau181, and p-Tau231 were individually coated onto ELISA plates. After blocking, the plates were incubated with serially diluted primary antibodies (anti-p-Tau217, anti-p-Tau181, anti-p-Tau231). Bound antibodies were detected using HRP-conjugated secondary antibodies, followed by TMB substrate for colorimetric quantification, with absorbance measured at 450 nm.

Results: GeneMedi is proud to offer pTau217/181/231 phosphorylated full-length protein. As shown in Figures A, B, and C: p-Tau217 full-length antigen specifically binds to anti-p-Tau217 antibodies (Figure A); p-Tau181 full-length antigen specifically binds to anti-p-Tau181 antibodies (Figure B); p-Tau231 full-length antigen specifically binds to anti-p-Tau231 antibodies (Figure C). These results demonstrate that pTau217/181/231 phosphorylated full-length antigens are phosphorylated at their respective sites, with minimal phosphorylation at other sites, ensuring high specificity and reliability for research and diagnostic applications.

Click to Zoom

Fig2. High specificity and reliability of p-Tau217/181/231 Phosphorylated Full-Length Antigens In ELISA.
A. p-Tau217 full-length antigen binds specifically to p-Tau217 antibodies.
B. p-Tau181 full-length antigen binds specifically to p-Tau181 antibodies.
C. p-Tau231 full-length antigen binds specifically to p-Tau231 antibodies.

3. In sandwich ELISA assays, GeneMedi's p-tau217 antibody and tau antibody pair can detect the full-length phosphorylated 217 protein but are unable to detect phosphorylated 217 peptides or non-phosphorylated proteins.

Click to Zoom

Click to Zoom

GMP-h-p-tau217-Ab01 is used as the capture antibody. When GMP-h-Tau-Ab03 is used as the detection antibody, the EC50 for detecting GMP-h-p-tau217-Ag02 is lower than GMP-h-Tau-Ab01, indicating GMP-h-Tau-Ab03 is more suitable as a detection antibody.
However, when detecting phosphorylated 217 peptide GMP-h-p-tau217-Ag01 or non-phosphorylated protein GMP-h-tau-Ag01, the EC50 remains high regardless of whether GMP-h-Tau-Ab03 or GMP-h-Tau-Ab01 is used, suggesting no binding for detecting peptide GMP-h-p-tau217-Ag01 or non-phosphorylated protein GMP-h-tau-Ag01 under these conditions.

Fig3. Sandwich ELISA Analysis of Full-Length Phosphorylated Tau 217 Antigen with Corresponding Phosphorylated Tau 217 Antibody and Total Tau Antibody.

A.This figure illustrates the detection efficacy of two different antibody combinations in Sandwich ELISA experiments targeting the GMP-h-p-tau217-Ag02 antigen (full length). The x-axis represents the antigen concentration displayed on a logarithmic scale (μg/ml), while the y-axis shows the corrected absorbance. The results indicate that the combination of GMP-h-p-tau217-Ab01 as the coating antibody and GMP-h-Tau-Ab01 as the detection antibody yields an EC50 of 76.55 ng/ml. Conversely, using GMP-h-p-tau217-Ab01 as the coating antibody and GMP-h-Tau-Ab03 as the detection antibody results in an EC50 of 39.02 ng/ml, demonstrating higher detection sensitivity at lower concentrations.

B.This figure demonstrates the detection results of two different detection antibodies (GMP-h-tau-Ab01 and GMP-h-tau-Ab03) against the GMP-h-tau-Ag01 antigen (full length) in an ELISA assay, using GMP-h-p-tau217-Ab01 as the coating antibody. The x-axis represents antigen concentration, displayed on a logarithmic scale (μg/ml); the y-axis shows corrected absorbance. The results reveal that when using GMP-h-tau-Ab03 as the detection antibody, the EC50 value reaches 20030 ng/ml, indicating a lower sensitivity to the antigen; whereas, when using GMP-h-tau-Ab01 as the detection antibody, the EC50 value soars to 4352000 ng/ml, demonstrating poor efficacy in detecting the antigen.

C. This figure illustrates the detection performance of four different antibody combinations in an ELISA assay targeting the GMP-h-p-tau217-Ag01 antigen (peptide). The x-axis represents antigen concentration, displayed on a logarithmic scale (μg/ml), while the y-axis shows the corrected absorbance. The curves in the figure show that all antibody combinations maintain relatively consistent absorbance changes across a range of low to high concentrations, indicating these results also reveal that the sensitivity of these four antibody combinations in detecting the GMP-h-p-tau217-Ag01 (peptide) antigen is relatively low.

4. Validation of High-Specificity p-Tau217/181/231 and Tau Antibody Pairs

The ELISA validation data demonstrates the exceptional specificity of p-Tau217/181/231 and tau antibody pairs: p-Tau217/Tau pair exclusively recognizes p-Tau217 full-length antigen (Figure A); p-Tau181/Tau pair shows selective binding to p-Tau181 full-length antigen (Figure B); p-Tau231/Tau pair specifically detects p-Tau231 full-length antigen (Figure C). The complete absence of cross-reactivity with non-target phospho-Tau isoforms confirms the superior specificity of these antibody pairs, making them ideal for precise Alzheimer's disease biomarker detection.

Fig4. High specificity and reliability of p-Tau217/181/231 and tau antibody pairs In ELISA.
A. p-Tau217/ tau antibody pair binds specifically to p-Tau217 full-length antigen.
B. p-Tau181/ tau antibody pair binds specifically to p-Tau181 full-length antigen.
C. p-Tau231/ tau antibody pair binds specifically to p-Tau231 full-length antigen.