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Because most blood is separated into its components, the WB is collected into sets that involve multiple connected bags. The blood first enters the primary bag, where it is mixed with anticoagulant–preservative solution. After collection, the WB is kept at a temperature either between 1°C and 6°C or between 20°C and 24°C depending on the intended use of the unit (Figure 5.1). If RBCs and plasma are to be produced, the blood is kept between 1°C and 6°C. The blood can be placed in a regular blood storage refrigerator or special insulated containers that contain ice to maintain the 1–6°C temperature. If platelets are to be prepared from the WB, the blood must be maintained at room temperature (20–24°C) because exposure to cold alters the platelets. Maintenance of the blood at room temperature is done by placing the units in containers specially designed to maintain that temperature. It is recognized that the blood will not attain the temperatures of the storage containers (1–6°C or 20–24°C) for several hours, but the blood must be placed in the environment that will begin to bring the temperature of the blood to the desired storage temperature.

Table 5.4 Content of anticoagulant–preservative solutions (mg in 63 mL).

Source: Fung MK, Eder A, Spitalnik SL, Westhoff CM, eds. Technical Manual, 19th edn. Bethesda, MD: American Association of Blood Banks, 2017, p. 132. © 2017 AABB. Reproduced with permission from AABB.

	CPD	CP2D	CPDA‐1
Sodium citrate, dehydrate	1660	1660	1660
Citric acid, anhydrous	188	206	188
Dextrose, monohydrate	1610	3220	2010
Monobasic sodium phosphate, monohydrate	140	140	140
Adenine	0	0	17.3

CPD, citrate–phosphate–dextrose; CP2D, citrate–phosphate–double dextrose; CPDA‐1, citrate–phosphate–dextrose adenin‐1.

Figure 5.1 Diagram showing unit of whole blood and integral plastic bag system used for preparing blood components.

High‐speed centrifuges that accommodate four or six units of WB are used to prepare the components. Important factors in the centrifuge techniques include the rotor size, centrifuge speed, time at maximum speed, and braking mechanism or deceleration phase. The WB is manipulated differently depending on the components desired (see later). After removal of the platelet‐rich plasma, the additive solution is added to the concentrated red cells for optimum red cell preservation (Figure 5.2). Several devices are now available that provide semiautomatic separation of WB. These are in limited use, but the concept has great potential.

Figure 5.2 Diagrammatic illustration of the separation of whole blood into red cells, plasma, and platelet concentrate.

Table 5.5 Content of additive solutions.

Source: Fung MK, Eder A, Spitalnik SL, Westhoff CM, ed. Technical Manual, 19th edn. Bethesda, MD: American Association of Blood Banks, 2017, p. 135. © 2017 AABB. Reproduced with permission from AABB.

	AS‐1 (Adsol)	AS‐3 (Nutricel)
Dextrose (glucose)	111	55
Adenine	2	2
NaH2PO4	–	–
Mannitol	41	–
NaCl	154	70
Na3‐citrate	–	23
Citric acid		2

NaH₂PO₄, monobasic sodium phosphate; NaCl, sodium chloride; Na₃‐citrate, trisodium citrate.

Table 5.6 Characteristics of red cells in AS‐1 (Adsol) for 42 days of storage.

Source: McCullough J. Transfusion medicine. In: Handin RI, Lux SE, Stossel TP, eds. Blood: Principles and Practice of Hematology. Philadelphia: Lippincott Williams & Wilkins, 2003, p. 2018. Reproduced with permission from Robert Handin.

	Days of storage
Indices	0	7	14	21	28	35	42
pH (at 37°C)	7.00	6.86	6.69	6.55	–	6.43	3.34
RBC ATP (mmol/g Hgb)	4.69	4.97	4.83	4.50	3.75	3.47	3.24
RBC DPG (mmol/g Hgb)	10.88	8.16	1.96	0.87	0.65	0.54	0.65
Supernatant sodium (mEq/L)	152	135	131	124	–	126	123
Supernatant potassium (mEq/L)	1.6	17	27	34	–	44	46
Supernatant glucose (mg/dL)	909	780	724	697	660	617	604
Hemolysis (%)	0.02	0.06	0.11	0.14	0.20	0.16	0.24

AS‐1 cells: N = 13; volume = 325 + 29 mL; hematocrit = 58% + 4%; mean red cell mass = 188 mL; mean supernatant volume = 136 mL; mean total hemoglobin = 19.3 g%.ATP, adenosine triphosphate; DPG, diphosphoglycerate; Hgb, hemoglobin; RBC, red blood cell.