RESUMO
BACKGROUND: The Korean Red Cross (KRC) has stored blood donor samples for 10 years under -20degrees C since 2004. These samples have been used for investigating transfusion related infections and for Look-back studies. We designed an experimental scheme to verify the stability of stored blood samples. METHODS: We collected and prepared samples such as blood donor samples (HBV, HCV, HIV nucleic acid positive; n=90), the HIV infected patient samples (n=20), the WHO nucleic acid international standards serologic positive samples (HBsAg, anti-HCV, anti-HIV; n=120) and the negative samples (n=20). The samples were aliquoted in cryo tubes with volumes of 0.5~5 mL and they were stored at -20~-30degrees C and -70~-80degrees C. We used enzyme immunoassay, chemiluminescence immunoassay and quantitative PCR for the base line and the follow up studies. The linear mixed statistical model using SAS 9.1 for windows was used for statistical analysis. RESULTS: The results of the baseline test of the stored samples showed a variable range of viral load (10(1)~10(7) IU/mL or copies/mL) and optical density (S/CO 3.0~500). The results of the stored samples after 6 month (n=82) did not show any significant differences compared to the baseline data for the viral loads (P>0.05) and the qualitative serologic tests. CONCLUSION: We established an experimental scheme to verify the stability of the stored blood donor samples. From now on, the stability of the stored samples is going to be monitored by every 6 month for 10 years.