Stored Red Blood Cells

Modern Medicine Relies on Red Blood Cells

Red blood cells (RBCs) are the most common type of cell found in the blood1 and are primarily responsible for delivering oxygen throughout the body.2 Over the years, processing and storage methods have dramatically improved the availability of RBCs for transfusion as a life-saving therapy.

Healthy RBCs contain a number of important elements including ATP and 2,3 DPG, which are critical to transporting and offloading oxygen to the tissues.3,4

RBC Storage is Affected by Donor Variability and Processing

Oxygen levels in RBCs vary between blood donors.5  As soon as blood is collected, RBCs begin to degrade as a result of oxidative damage. Such degradation combined with storage in an oxygen permeable bag reduces the quality, viability, and functionality of RBCs, thereby affecting their ability to deliver oxygen in a patient following transfusion.6,7,8,9 This variability is exacerbated by differing storage times for each RBC unit prior to transfusion.10

The images in the figure above are from Bardyn et al., and are component-separated RBC units tested on Day 0 that were tested with a co-oximeter to measure their actual oxygen saturation (%SO2) levels. This is an example of RBC unit color as function of oxygen saturation level. It is the Hb that gives their red color to the RBCs, the tint of which depends on how many oxygen molecules are bound by the heme group. RBCs with higher oxygen levels appear scarlet (images on the left) and the images with lower oxygen levels appear darker in color. (images on the right).11

What’s going on in the bag during storage?

See a depiction of the degradation process that occurs during RBC storage and how it impacts the major functions of RBCs in the 3D animation below.

[1] Dean L. Chapter 1: Blood and the cells it contains. Blood Groups and Red Cell Antigens. Bethesda (MD): National Center for Biotechnology Information (US); 2005. Accessed March 15, 2024. [2] Yoshida T, Prudent M, D’Alessandro A. Red blood cell storage lesion: causes and potential clinical consequences. Blood Transfus. 2019;17(1):27-52. [3] Dailey JF. Chapter 4: The red blood cells and oxygen transport. Manley J, eds. In: Dailey’s Notes on Blood. 4th, ed. Cache River Press; 2002:26-33. [4] Kor DJ, Van Buskirk C, and Gajic O. Red blood cell storage lesion. Bosnian Journal of Basic Medical Sciences. 2009;9(Supp 1):S21-S27. [5] Yoshida T, Whitley PH, Rugg N, et al. Oxygen saturation of collected rbc products is donor dependent. Abstract presented at: The Association for the Advancement of Blood & Biotherapies; October 19-22, 2019; San Antonio, TX. [6] Orlov D and Karkouti K. The pathophysiology and consequences of red blood cell storage. Anesthesia. 2015;70 (Suppl. 1):29-37. [7] Yoshida T, Shevkoplyas SS. Anaerobic storage of red blood cells. Blood Transfus. 2010;8(4):220-36. [8] Mustafa I, Al Marwani A, Nasr KM, Kano NA, and Hadwan T. Time dependent assessment of morphological changes: leukodepleted packed red blood cells stored in SAGM. BioMed Research Intl. 2016. Doi: [9] DeSantis SM, Brown DW, Jones AR, et al. Characterizing red blood cell age exposure in massive transfusion therapy: the scalar age of blood index (SBI). Transfusion. 2019; 59;2699-2708 [10] DePew S, Marques M, Patel R, et al. Estimating oxidative stress burden of multiple blood transfusions in trauma patients. [Abstract P-BB-22]. Transfusion. 2020; 60(suppl 5). [11] Bardyn M, Martin A, Dögnitz N, et al. Oxygen in red blood cell concentrates: influence of donors’ characteristics and blood processing. Front. Physiol. 2020;11:616457. Doi: 10.3389/fphys.2020.616457.