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Published on: October 11, 2016
[Studies on the method to quantify PPD and its adsorption onto glass-surface]
S Niinuma1, K Kawajiri, I Toida
1Japan BCG Labortory, Tokyo, Japan.
Kekkaku : [Tuberculosis]
|December 1, 1995
Summary
Purified protein derivative (PPD) potency decreases rapidly at low concentrations due to adsorption onto container surfaces. A new ELISA method quantifies this PPD adsorption, revealing key factors influencing its rate and extent.
Area of Science:
- Biochemistry
- Immunology
- Analytical Chemistry
Context:
- Purified protein derivative (PPD) is crucial for tuberculosis skin testing.
- PPD potency diminishes rapidly at clinically relevant low concentrations.
- Previous methods for studying PPD adsorption were not quantitative or reproducible.
Purpose:
- To develop a novel, quantitative ELISA method for measuring low PPD concentrations.
- To analyze the adsorption of PPD onto glass surfaces using the new ELISA method.
- To characterize the factors influencing PPD adsorption kinetics and extent.
Summary:
- PPD adsorption onto glass is rapid initially, then slows, influenced by temperature and PPD concentration.
- Adsorption is directly proportional to glass surface area and solution volume.
- Lower PPD concentrations and higher temperatures increase adsorption rates, with significant 'volume effects' observed.
Impact:
- Provides a reliable, quantitative method (ELISA) to study PPD adsorption.
- Identifies critical handling parameters (temperature, concentration, volume) affecting PPD stability.
- Highlights the importance of adhering to manufacturer guidelines for PPD preparations, especially single-dose vials, to maintain diagnostic accuracy.
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