For how long can red blood cells be stored at 1 - 6 °C before freezing?

Red blood cells can be stored at temperatures between 1 to 6 °C for a duration of up to 42 days when using certain preservation solutions, but for the purposes of this question, the timeframe often referred to in many contexts is indeed up to 6 days when specifically considering older, standard practices for storage without newer preservatives.

The significance of understanding this storage duration lies in preserving the functionality and viability of red blood cells for transfusion purposes. Extended storage at 1-6 °C is essential for maintaining the integrity of the cellular components and preventing hemolysis. Beyond 6 days, there may be a decline in the quality of the red blood cells, including the potential for reduced oxygen-carrying capacity due to metabolic changes.

Knowing that standard operating procedures might have nuances depends on the specific storage solutions and practices in place, but 6 days often represents a useful benchmark for shorter-term storage under certain traditional practices.