A micromethod for clotting tests and coagulation factor assays

Area of Science:

• Hematology
• Clinical Chemistry
• Microfluidics

Background:

• Traditional coagulation assays, like the partial thromboplastin time (PTT), often require significant sample volumes.
• The need for micro-volume testing is increasing in specialized diagnostics and research settings.
• Existing microtechniques may lack the precision or simplicity required for routine clinical use.

Purpose of the Study:

• To describe a novel, simple microtechnique for performing partial thromboplastin time with kaolin (PTT-K) tests.
• To demonstrate the feasibility of using minimal plasma volumes (≤2 µL) for PTT-K assays.
• To validate the application of this microtechnique for single-stage coagulation factor assays using <1 µL of test solution.

Main Methods:

• Sequential loading of reagents and test plasma into a 10 µL long-needle syringe.
• Introduction of the mixture into a micro test-tube secured in a water bath.
• Determination of the endpoint by observing the clearing of kaolin turbidity during stirring.

Main Results:

• The microtechnique successfully performs PTT-K tests with 2 µL or less of plasma.
• Single-stage factor assays can be conducted with less than 1 µL of test solution.
• Excellent correlation was observed between the results from this microtechnique and conventional methods.

Conclusions:

• This microtechnique offers a simplified and efficient approach for PTT-K and coagulation factor assays.
• The method's low sample volume requirement makes it suitable for pediatric, neonatal, or resource-limited settings.
• The validated accuracy ensures reliable diagnostic information from minimal blood samples.