Abstract: Objective To investigate the stability time of HbA1c samples in 4 different storage temperature conditions. Methods 20 samples with different HbA1c levels were collected. Each sample is thoroughly mixed and distributed into 45 parts. In each level group, a random selected sample was measured immediately, and the remaining samples were immediately grouped and stored at room temperature (22 ~ 25℃), refrigerated (2 ~ 8℃), frozen (≤-20℃), cryopreservation (≤-70℃), which were measured at 1,2,3,7,15,20 day and 1,2,3,6 month and 1y respectively. HbA1c levels were detected by HPLC method. The changes of average level of HbA1c versus time with 4 different temperatures were observed and the stability of HbA1c was evaluated by different method or judgment. Results Judge by different less than 6%, HbA1c was stable for 1 year at -70℃; HbA1c in low concentration levels was stable for 7 days at -20℃, while in high concentration levels could be stable for 20 days with 11.2% average annual decline rate. HbA1c at room temperature and refrigerated storage conditions could be stable for 3 days, till 7 days, HbA1c level dropped by average -9.1% and -7.1% respectively. Conclusions This study provides a basis to formulate and improve HbA1c specimens preservation conditions. The Cryopreservation is more favorable for large-scale epidemiological studies of HbA1c.

Key words: HbA1c, Stability