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A Magnetic Bead-Based Sensor for the Quantification of Multiple Prostate Cancer Biomarkers.

Jokerst JV, Chen Z, Xu L, Nolley R, Chang E, Mitchell B, Brooks JD, Gambhir SS - PLoS ONE (2015)

Bottom Line: The results were analyzed with receiver operator characteristic curve analysis.The highest AUC discrimination was achieved with a spondin-2 OR free/total PSA operation--the area under the curve was 0.84 with a p value below 10(-6).This bead-based system offers important advantages in assay building including low cost, high throughput, and rapid identification of an optimal matched antibody pair.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California, United States of America.

ABSTRACT
Novel biomarker assays and upgraded analytical tools are urgently needed to accurately discriminate benign prostatic hypertrophy (BPH) from prostate cancer (CaP). To address this unmet clinical need, we report a piezeoelectric/magnetic bead-based assay to quantitate prostate specific antigen (PSA; free and total), prostatic acid phosphatase, carbonic anhydrase 1 (CA1), osteonectin, IL-6 soluble receptor (IL-6sr), and spondin-2. We used the sensor to measure these seven proteins in serum samples from 120 benign prostate hypertrophy patients and 100 Gleason score 6 and 7 CaP using serum samples previously collected and banked. The results were analyzed with receiver operator characteristic curve analysis. There were significant differences between BPH and CaP patients in the PSA, CA1, and spondin-2 assays. The highest AUC discrimination was achieved with a spondin-2 OR free/total PSA operation--the area under the curve was 0.84 with a p value below 10(-6). Some of these data seem to contradict previous reports and highlight the importance of sample selection and proper assay building in the development of biomarker measurement schemes. This bead-based system offers important advantages in assay building including low cost, high throughput, and rapid identification of an optimal matched antibody pair.

No MeSH data available.


Related in: MedlinePlus

Detection Scheme.A. The c.Ab. is covalently bound to a magnetic bead that is incubated with sample and fluorescein-tagged d.Ab. This sample is introduced into a flow cell capped with a piezo-electric membrane coated with an anti-fluorescein antibody. An electromagnet above the membrane is controlled with embedded software. B. Upon magnetic perturbation, all beads (black circles) move towards the membrane (Bi), and beads with a completed immunocomplex (black circles coated with red dots) bind to the anti-fluorescein antibody (Bii). After the field is removed and flow restored, only beads with a completed immunocomplex remain bound (Biii). These beads alter the oscillation of the membrane (represented as orange sinusoidal curve), which is interpreted as signal in arbitrary units [36]. See S1 Video. In B, the solid blue line labeled Pos refers to beads in the presence of antigen, and the dotted red line labeled Neg refers to beads in the absence of antigen.
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pone.0139484.g001: Detection Scheme.A. The c.Ab. is covalently bound to a magnetic bead that is incubated with sample and fluorescein-tagged d.Ab. This sample is introduced into a flow cell capped with a piezo-electric membrane coated with an anti-fluorescein antibody. An electromagnet above the membrane is controlled with embedded software. B. Upon magnetic perturbation, all beads (black circles) move towards the membrane (Bi), and beads with a completed immunocomplex (black circles coated with red dots) bind to the anti-fluorescein antibody (Bii). After the field is removed and flow restored, only beads with a completed immunocomplex remain bound (Biii). These beads alter the oscillation of the membrane (represented as orange sinusoidal curve), which is interpreted as signal in arbitrary units [36]. See S1 Video. In B, the solid blue line labeled Pos refers to beads in the presence of antigen, and the dotted red line labeled Neg refers to beads in the absence of antigen.

Mentions: This system consists of a disposable 8-channel cartridge connected to fluidic handling robotics and an electrically controlled magnet. Samples and standards were prepared at 1:10–1:1000 dilution factor and plated into 96 well plates along with beads and fluorescent antibody. The specimens were prepared by mixing 80 μL of sample or standard with 20 μL of beads coated with c.Ab (900,000 beads/mL) and 20 μL of fluorescein-labeled d.Ab (1200 ng/mL). These reagents form an immunocomplex sandwich in the presence of the biomarker antigen (Fig 1A).


A Magnetic Bead-Based Sensor for the Quantification of Multiple Prostate Cancer Biomarkers.

Jokerst JV, Chen Z, Xu L, Nolley R, Chang E, Mitchell B, Brooks JD, Gambhir SS - PLoS ONE (2015)

Detection Scheme.A. The c.Ab. is covalently bound to a magnetic bead that is incubated with sample and fluorescein-tagged d.Ab. This sample is introduced into a flow cell capped with a piezo-electric membrane coated with an anti-fluorescein antibody. An electromagnet above the membrane is controlled with embedded software. B. Upon magnetic perturbation, all beads (black circles) move towards the membrane (Bi), and beads with a completed immunocomplex (black circles coated with red dots) bind to the anti-fluorescein antibody (Bii). After the field is removed and flow restored, only beads with a completed immunocomplex remain bound (Biii). These beads alter the oscillation of the membrane (represented as orange sinusoidal curve), which is interpreted as signal in arbitrary units [36]. See S1 Video. In B, the solid blue line labeled Pos refers to beads in the presence of antigen, and the dotted red line labeled Neg refers to beads in the absence of antigen.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4589536&req=5

pone.0139484.g001: Detection Scheme.A. The c.Ab. is covalently bound to a magnetic bead that is incubated with sample and fluorescein-tagged d.Ab. This sample is introduced into a flow cell capped with a piezo-electric membrane coated with an anti-fluorescein antibody. An electromagnet above the membrane is controlled with embedded software. B. Upon magnetic perturbation, all beads (black circles) move towards the membrane (Bi), and beads with a completed immunocomplex (black circles coated with red dots) bind to the anti-fluorescein antibody (Bii). After the field is removed and flow restored, only beads with a completed immunocomplex remain bound (Biii). These beads alter the oscillation of the membrane (represented as orange sinusoidal curve), which is interpreted as signal in arbitrary units [36]. See S1 Video. In B, the solid blue line labeled Pos refers to beads in the presence of antigen, and the dotted red line labeled Neg refers to beads in the absence of antigen.
Mentions: This system consists of a disposable 8-channel cartridge connected to fluidic handling robotics and an electrically controlled magnet. Samples and standards were prepared at 1:10–1:1000 dilution factor and plated into 96 well plates along with beads and fluorescent antibody. The specimens were prepared by mixing 80 μL of sample or standard with 20 μL of beads coated with c.Ab (900,000 beads/mL) and 20 μL of fluorescein-labeled d.Ab (1200 ng/mL). These reagents form an immunocomplex sandwich in the presence of the biomarker antigen (Fig 1A).

Bottom Line: The results were analyzed with receiver operator characteristic curve analysis.The highest AUC discrimination was achieved with a spondin-2 OR free/total PSA operation--the area under the curve was 0.84 with a p value below 10(-6).This bead-based system offers important advantages in assay building including low cost, high throughput, and rapid identification of an optimal matched antibody pair.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California, United States of America.

ABSTRACT
Novel biomarker assays and upgraded analytical tools are urgently needed to accurately discriminate benign prostatic hypertrophy (BPH) from prostate cancer (CaP). To address this unmet clinical need, we report a piezeoelectric/magnetic bead-based assay to quantitate prostate specific antigen (PSA; free and total), prostatic acid phosphatase, carbonic anhydrase 1 (CA1), osteonectin, IL-6 soluble receptor (IL-6sr), and spondin-2. We used the sensor to measure these seven proteins in serum samples from 120 benign prostate hypertrophy patients and 100 Gleason score 6 and 7 CaP using serum samples previously collected and banked. The results were analyzed with receiver operator characteristic curve analysis. There were significant differences between BPH and CaP patients in the PSA, CA1, and spondin-2 assays. The highest AUC discrimination was achieved with a spondin-2 OR free/total PSA operation--the area under the curve was 0.84 with a p value below 10(-6). Some of these data seem to contradict previous reports and highlight the importance of sample selection and proper assay building in the development of biomarker measurement schemes. This bead-based system offers important advantages in assay building including low cost, high throughput, and rapid identification of an optimal matched antibody pair.

No MeSH data available.


Related in: MedlinePlus