A rapid paper-based blood typing method from droplet wicking.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Point-of-Care Diagnostics

Background:

• Traditional gel column agglutination is standard in hospitals but lacks automation and speed.
• Current paper-based diagnostics are often single-use, time-consuming, and not easily automated for large-scale use.

Purpose of the Study:

• To develop a novel, rapid, and scalable paper-based blood typing method.
• To achieve blood typing results suitable for large-scale automation in under ten seconds.

Main Methods:

• A drop of antibody solution and a drop of blood are placed on paper, and blood stain area evolution over time is measured.
• Analysis of paper type, red blood cell concentration, antibody specificity (A, B, D), and antibody dilution effects on sensitivity and reproducibility.

Main Results:

• Positive reactions show significantly slower stain growth rates and smaller final stain sizes compared to negative reactions.
• Low-density, thin paper enhances sensitivity; optimal red blood cell concentration balances wicking, reaction strength, and contrast.
• A and B antibodies are more sensitive than D, but D antigen identification is still successful.

Conclusions:

• This paper-based method offers the fastest blood typing test suitable for large-scale automation.
• The technique has the potential to significantly reduce blood typing time and cost.
• Enables the design of new high-throughput, fully automatable blood typing systems.