Barcode-Based SlipChip for High-Multiplexed and Trace Sample Digital Quantification with Femtomolar Sensitivity.

Area of Science:

• Biotechnology
• Assay Development
• Biomarker Discovery

Background:

• Digital ELISA enhances protein biomarker detection sensitivity.
• Current digital ELISA methods struggle with multiplexing low-abundance targets in trace samples.
• Improved detection multiplicity and sensitivity are needed for complex biological samples.

Purpose of the Study:

• To develop a simple digital ELISA platform, the Barcodes Integrated SlipChip (BIS-chip), for ultrasensitive, multiplexed protein identification from trace samples.
• To enhance detection multiplicity and sensitivity beyond existing digital ELISA technologies.
• To validate the BIS-chip's clinical applicability for diagnosing conditions like oral lichenoid reactions (OLRs).

Main Methods:

• The BIS-chip utilizes a two-step loading method to ensure specificity for 10-plex target detection.
• High bead-loading efficiency enhances assay sensitivity for each target.
• Digital "On" and "Off" signals are counted to quantify 10 cytokines with femtogram per milliliter (fg/mL) limits of detection (LoD).

Main Results:

• The BIS-chip achieved a sensitivity improvement of several orders of magnitude compared to standard multiplexed suspension array technology.
• 10 cytokines were simultaneously measured from 20 μL of intralesional plasma from OLR patients.
• Machine-learning algorithms supported the development of OLR diagnostic models with 95.7% sensitivity and 100% specificity.

Conclusions:

• The BIS-chip offers exceptional detection multiplicity and ultrasensitivity for quantitative analysis of low-abundance biomarkers in trace samples.
• Its straightforward workflow provides an innovative solution for challenging clinical diagnostics.
• The BIS-chip demonstrates significant potential for advancing biomarker analysis in various biological and clinical applications.