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Updated: Apr 15, 2026
An Optimized Hemagglutination Inhibition HI Assay to Quantify Influenza-specific Antibody Titers
Published on: December 1, 2017
Determination of specimen storage conditions for measuring isoagglutinin titers
Hee Seoung Seo1, Ji Yeon Sohn1, Joo-Hyoung Hwang1
1Department of Laboratory Medicine, Center for Diagnostic Oncology, Hospital and Research Institute, National Cancer Center, Goyang, Republic of Korea.
Insights
Serum specimens for isoagglutinin titration can be stored up to 96 hours at room temperature or 4°C without significantly impacting titer results. This flexibility allows for regular scheduling of blood bank tests.
Area of Science:
- Transfusion Medicine
- Immunohematology
Background:
- Accurate isoagglutinin titration is crucial for blood transfusion safety.
- Standardized specimen storage conditions are necessary to ensure reliable test results.
Purpose of the Study:
- To determine optimal storage conditions for isoagglutinin titration.
- To evaluate the impact of storage time and temperature on titer stability.
Main Methods:
- Serum specimens from 60 individuals were stored at room temperature (25°C) or 4°C.
- Samples were tested every 24 hours up to 96 hours using immediate spin (IS) and dithiothreitol-anti-human globulin (DTT-AHG) methods.
- Titer results were compared to baseline, with clinically significant differences defined as >4-fold changes.
Main Results:
- Specimens stored at room temperature showed minimal titer differences (≤2-fold) up to 96 hours for both IS and DTT-AHG methods.
- Refrigerated specimens also exhibited similar minimal titer changes within the 96-hour storage period.
- The majority of specimens maintained stable titers under both storage conditions.
Conclusions:
- Specimen storage up to 96 hours at room temperature or 4°C does not significantly alter isoagglutinin titers.
- These findings support the feasibility of regular scheduling for isoagglutinin testing.
- Current storage protocols are adequate for maintaining sample integrity for routine immunohematology testing.
Background:
This study aimed to determine the optimal specimen storage conditions for isoagglutinin titration by changing storage time and temperature.
Study Design And Methods:
Serum specimens from 60 individuals were stored at room temperature (RT, 25 °C) or at 4 °C and tested every 24 hours until 96 hours by the immediate spin (IS) method and the anti-human globulin method using dithiothreitol (DTT-AHG). These titer results were compared with the titers which were measured when the samples arrived. The titer endpoint was defined as the highest dilution, with clinically meaningful differences defined as more than 4-fold differences (two serial dilutions) in titer.
Results:
Of the specimens stored at RT for 24, 48, 72, and 96 hours, 5%, 12%, 12%, and 12%, respectively, showed two-fold (one dilution) differences by the IS method, and 8%, 8%, 8%, and 10%, respectively, showed two-fold (one dilution) differences with the DTT-AHG method. Of the specimens refrigerated for 24, 48, 72, and 96 hours, 8%, 10%, 13%, and 13%, respectively, showed two-fold (one dilution differences) by the IS method, and 13%, 12%, 12%, and 12%, respectively, showed two-fold (one dilution) differences with the DTT-AHG method.
Conclusions:
Specimens stored for up to 96 hours at RT and 4 °C showed similar titers using the IS and DTT-AHG methods. These findings suggest that tests can be scheduled regularly.
