Plasma collection

Plasma Collection. Human plasma is collected from donors either as a plasma donation, from which the red cells and other cellular components have been removed and returned to the donor by a process known as plasmapheresis, or in the form of a whole blood donation. These are referred to as source plasma and recovered plasma, respectively (Fig. 1). In both instances the donation is collected into a solution of anticoagulant (146) to prevent the donation from clotting and to maintain the stabiUty of the various constituents. Regulations in place to safeguard the donor specify both the frequency of donation and the volume that can be taken on each occasion (147). 

Procedures for the collection of whole blood are similar throughout the world. An interval from at least 8 weeks (United States) to 12 weeks (United Kingdom) is required between a donation of 450 mL blood, which yields about 250 mL plasma. In some countries a smaller volume of blood is collected, eg, 350—400 mL in Italy, Greece, and Turkey and as Httie as 250 mL in some Asian countries (147). Regulations concerning plasmapheresis donations vary more widely across the world eg, up to 300 mL of plasma can be taken in Europe in contrast to 1000 mL in the United States, both on a weekly basis. Consequentiy, both the mode of donation and the country in which it is given can have a profound effect on plasma collection (Table 6). 

The question often arises whether a sample must be analyzed immediately or can be stored, and if so, under what conditions and for how long (B4a, H5a, W9a). Freshly drawn blood maintained anaerobically (A3) at 38 C decreases in pH at the rate of —0.062 unit per hour and in pCOj, at 4.8 1.3 mg Hg per hour. At 0-4°C, the change is minimal — 0.006 0.004 pH unit and 0.6 0.06 mm Hg. There has been controversy concerning the use of minerol oil to maintain specimens for carbon dioxide analysis (G2). Paulsen found that values of total carbon dioxide in plasma collected in stoppered tubes with and without paraflSn oil were identical if the tubes without oil were completely filled to the stopper (P4). The loss of carbon dioxide in tubes stored at room temperature without oil was about 6 mEq/1 in 2.5-4 hours. The problem for the laboratory is unfilled tubes and the storage of separated serum or plasma before analysis and in plastic cups during continuous-flow procedures. 

Lignocaine, originally introduced as a local anesthetic, is now widely used for the treatment and prevention of ventricular arrhythmias. When used for this purpose, it is usually administered either by intramuscular injection, or as a bolus intravenously, or, more commonly, by constant intravenous infusion. For clinical purposes, lignocaine measurements arc usually carried out on plasma collected either while the patient is receiving a constant intravenous infusion or at a specified time after the last intramuscular injection. Colorimetric methods have been used in the past (S29), but, because they lack both sensitivity and specificity, may yield false and misleading results. They have largely been replaced by GLC techniques (A3, El, K5). 

Pooled plasma collected from healthy subjects is used for standards preparation to avoid matrix effects and for internal control. Pooled plasma is kept in 0.5-ml aliquots at -20 C until required. 

A minimum of 2 ml EDTA blood is placed immediately on ice and centrifuged within 30 min at 2000 xg for 5 min at 4°C. Plasma is immediately deproteinised by adding 1 ml to 0.625 ml of 10% 4 and mixing thoroughly by vortex. The mixture is frozen and stored at -70°C until analysis. 1-ml aliquots of pooled plasma collected from healthy subjects are prepared and stored in the same way and are used to prepare AdoMet and AdoHcy calibration standards to allow for matrix effects and also as an internal quality control. CSF is collected in plain tubes and kept at -70°C until analysis. 

Today all blood for transfusion is collected in plastic bags, and most of the plasma is immediately separated by the collector. In addition, source plasma collected by apheresis as a licensed product provides approximately 80% of the U.S. plasma supply [12]. The FDA still permits unlicensed recovered plasma without FDA-defined specifications to move interstate under short supply, however. This solution to the supply dilemma requires the final product manufacturers to assume the responsibility for assuring that their source materials are appropriate and effective in their manufacturing process. 

The need to transfuse blood components such as plasma, platelets, factor VIII, in addition to red blood cells (RBC) has generated the development of plasmapheresis (plasma separation from whole blood) and more generally that of apheresis (fractionation of blood components). Plasma collection from donors by centrifugation of blood bags began only in 1944. This technique was extended to therapeutic plasma purification in 1950, but RBCs were fragilized by the centrifugation and the plasma was not completely platelet-free. 

In contrast to hemodialysis that uses ultrafiltration membranes, plasma separation (also called plasmapheresis) requires microfiltration membranes with a pore size from 0.2 to 0.6 pm, in order to transmit all proteins and lipids, including LDL cholesterol (2000kDa) and retain completely platelets (2 pm diameter), red blood cells (8 pm diameter) and white blood cells. Thus, membrane plasmapheresis can yield high-quality platelet-free plasma and red cells can be either continuously returned to the donor or saved in another bag for blood transfusion. But it is important, in the case of plasma collection from donors, to minimize the membrane area, in order to reduce the cost of disposable hollow-fiber filters and to avoid the risk of hemolysis (free hemoglobin release) due to RBC damage by contact at the membrane if the pressure difference across the membrane is too high. 

The Baxter Autopheresis C System for Plasma Collection from Donors... 

Figure 18.7 Schematic of rotating cylindrical filter for plasma collection from donors.

Membranes used for therapeutic plasma separation have the same characteristics as those used for plasma collection from donors, but their area is larger as the amount... 

To minimize interference between the different plasma collection schemes used it was decided to use a spatially separated system. The antiproton collection, cooling, and compression is housed in the same superconducting magnet system as the recombination trap, but the positron accumulator is a stand-alone system connected to the main apparatus by a beam line incorporating differential pumping and a fast valve. Figure 1 shows a schematic lay-out of the apparatus and the following sub-sections describe the individual parts of the apparatus in more detail. 

Fiala, S. A study on the iron-binding protein of plasma. Collection Chech. Chem. Commun. 14, 287 (1949). 

Normal intact plasma, collected in 0.1 vol. ACD, rendered platelet-poor by centrifugation, and stored in polystyrene tubes (Falcon Plastics Div., Becton, Dickinson, Co., Oxnard, Calif.) at —40°C was used within 4 hrs after thawing. 

In this case digoxin was recovered from the plasma collection bags, but the total amount recovered seems to have been less than 100 pg, so the efficacy of plasma exchange was not clear. 

Heal JM, Bailey G, Helphingstine C, Thiem PA, Leddy JP, Buchholz DH, Nusbacher J. Non-centrifugal plasma collection using cross-flow membrane plasmapheresis. Vox Sang 1983 44(3) 156-66. 

An example of this overall approach in elucidating novel bioactivation pathways is highlighted with studies on the potassium channel opener, maxipost (BMS-204352) (Figure 6.2), which undergoes a unique P450-mediated bioactivation reaction in rats, dogs, and humans to yield an electrophilic o-quinone-methide intermediate, which covalently binds to albumin in vivo in animals and human.33-34 Acidic hydrolysis of plasma collected after intravenous administration of [14C]-BMS-204352 to rats and human led to the characterization of a... 

The choice of container for samples is important, since contamination from rubber, cork, and colored plastics can be a problem. For blood plasma, collection plastic tubes with lithium heparin as an anticoagulant are suitable for most analyses. For blood serum, plain glass containers can be used. For the uitratrace metals (Mn, Cr), special arrangements have to be made to collect blood via plastic cannulae or silanized steel needles, and then the sample is placed into acid-washed containers. Trace metal vacutainers are avahabie commercially. It is good practice to run dilute acid blanks through all the containers and collection systems to ensure that all batches remain as free from contamination as possible. 

EDTA forms stable complexes with Ca and Mg ions in aqueous solution. Ca and Mg are present in blood plasma at about 2.2-2.5mmol 1 and 0.6-0.8 mmol L respectively and about 30-40% of both metals is protein bound. The 4(X) MHz H NMR spectra of human blood plasma collected using an EDTA anticoagulant has been reported to give well-resolved signals from... 

National Facility for Marine Cyanobacterial Germ Plasma Collection at Bharathidasan University, Trichy... 

Plasma Collection. Blood samples were collected from all animals at 0, 2, 4, 6, 12, 18 and 24 hours after the devices were inserted, then once daily until Day 10. On Days 13, 18, and 21, blood samples were withdrawn again followed by weekly collections between Day 21 and Day 84. Blood samples were subsequently taken on Days 86, 88 and Day 90, and then daily until the end of the in-life study when all the devices had been depleted. Approximately 10 mL of blood was collected from all animals in VACUTAINER tubes containing heparin at each sampling point. The blood was immediately centrifuged at 2(XX) rpm for ten minutes and the plasma was stored frozen until extraction. 

Only blood, or plasma collected in centres subject to inspection and approved by a competent authority should be processed. 

The labels on single units of plasma stored before pooling and fractionation should bear at least the identification number of the donation, the name and address of the plasma collection center, the batch number of the container, the storage temperature, the total volume or weight of the plasma, the quantity and type of the anticoagulant used and the date of collection and/or separation. 

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