任何质控物质中的目标核酸，无论是来自于患者样品还是替代品（人工制造），都会随着时间的推移而降解。由于核酸酶、冻融循环或其他影响，质控物质可能发生降解。一般来说，质控物质存档的时间越长，样品中可用的目标核酸的数量就越少。根据对照品的稳定性，可能需要定期开发新的对照或从制造商那里重新供应对照。

参考文献

[1] ISO. Medical devices – Application of risk management to medical devices. ISO 14971. Geneva, Switzerland: International Organization for Standardization; 2007.

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[3] Dowell SF, Peeling RW, Boman J, et al, and the C. pneumoniae workshop participants. Standardizing Chlamydia pneumoniae assays: Recommendations from the Centers for Disease Control and Prevention (USA) and the Laboratory Centre for Disease Control (Canada). Clin Infec Dis. 2001;33(4):492-503.