When testing sera for IFA-ANA, what is the best storage temperature for samples to be tested 6 days after drawing?

The best storage temperature for samples tested by indirect immunofluorescence assay for antinuclear antibodies (IFA-ANA) is 5°C ± 2°C. This temperature range helps maintain the stability of the antibodies present in the serum, ensuring that the samples remain suitable for testing even after several days of storage.

At this temperature, the integrity of the antibodies is preserved, reducing the risk of degradation that may occur at higher temperatures or in a frozen state. When samples are stored at -20°C, there may be a risk of denaturation or changes in the antibody structure, which could lead to inaccurate results. Storing at room temperature can also lead to degradation or loss of antibody activity due to higher temperatures and the potential for microbial growth.

Storing samples at 4°C, while better than room temperature, does not provide the specific controlled environment that the 5°C ± 2°C range offers. Maintaining this optimal range for storage is crucial for assay reliability and to ensure accurate results during the testing process.