Plasmas preparation

A universial anticoagulant does not exist, and it is therefore necessary to use, in clinical chemical analysis, serum or plasma prepared with a variety of anticoagulants. The role of the anticoagulant and preservatives on the observed value has been reviewed by Caraway (C2, C4) and by Winsten (Wll). 

Plasma prepared with strong chelators such as ethylene diamine tetraacetic acid (EDTA) may act as peptidase inhibitors for metalloproteases and peptidases using divalent cations as cofactors (28). 

Blood is taken aseptically into a flask containing heparin (2500 I.U./100 ml blood). Pularin (Evans Medical Co. Appendix 3) is a suitable source of heparin without preservative. The blood is allowed to stand at room temperature for 40 min and the leukocyte-rich plasma is then withdrawn aseptically and centrifuged at 400 g for 15 min at room temperature. The supernatant is withdrawn and recentrifuged at 1000 g for 10 min at room temperature to give a cell free autologous plasma preparation which can be stored at — 20°C. The cell sediment is resuspended in l/10th the initial volume of autologous plasma. 

At each observation time point three rats are put in the box for anesthesia separately (especially critical at early time points a staggered approach makes sense), which is permanently flushed with narcosis gas. The cover is closed and the rat is left there until complete apnoea. Taking the rat outside the box again the reflex comealis is proven. When the reflex is extinguished the vessels lateral below the throat are cut with the scalpel. The blood pouring out is collected in the small evaporating basins which already contain small amounts of heparin-sodium in cases where plasma preparation is intended (instead of serum). 

Fibrinogen adsorption from citrated blood plasma onto Silastic, poly-(HEMA)/Silastic and poly (NVP)/Silastic have been measured twice with two separate plasma preparations made from the blood of separate... 

In a group of six children with acute thrombocytopenia and bone marrow megakaryocytic hyperplasia, the blood plasma, prepared as previously described, showed, in each case, an acid phosphatase activity, as determined by Gutman s method, that was higher than the mean value for that age (p = 0.02). The p value for the comparison of the group as a whole with normals was between 0.01 and 0.02. In all six of these patients the plasma acid phosphatase values returned to normal or near normal levels as the thrombocytopenia was corrected. Oski et al. (02) also studied 15 cases of chronic idiopathic thrombocytopenic purpura in whom the bone marrow showed normal to increased numbers of megakaryocytes. Of these, 13 showed plasma acid phosphatase values that were elevated above the normal mean for their age, albeit some of these differences were small. However, these elevations were statistically significant with a p value less than 0.01. 

Genetically, determined clotting diseases include classical haemophilia, which is due to lack of factor VIII, and there is another form of haemophilia due to deficiency of factor IX (Christmas factor). These are treated by giving fresh donor blood or plasma, preparations of factor VIII or factor IX, or increasingly as one of the recombinant versions which are becoming available. 

Plasma preparation tube l, . . K2EDTA (dry additive)/polymer gel/sdica Opalescent white Opalescent white... 

The Plasma Preparation Tube (Becton Dickinson, Franklin Lakes, New Jersey) is a plastic evacuated tube used for tire collection of venous blood that upon centrifugation separates undiluted plasma for use in molecular diagnostic test methods. 

Holodniy M, Rainen L, Herman S, Yen-Lieberman B, Stability of plasma human immunodeficiency virus load in VACUTAINER PPT plasma preparation tubes during overnight shipment, J Clin Microbiol 2000 38 323-6. 

Figure 9 Typical quantitation using linear regression phenytoin in rat plasma prepared using a liquid-liquid extraction as follows 5-5000 ng/mL, 0.25 mL/min, 50/50 ACN/ H20, APCI negative ion PE Sciex API 3000.

FIGURE 11.6 Comparison of infusion chromatograms generated with (A) APCI, and (B) ESI. The matrix in this case was dog plasma prepared by protein precipitation. Analysis was performed by isocratic LC-MS/MS with a 2.1 x 50-mm Zorbax SB-C18 column at a flowrate of 0.5 mL/min (APCI) or 0.25 mL/min (ESI). Postcolumn infusion of urapidil was adjusted to achieve similar analyte delivery to each source. Detection of urapidil occurred by SRM. (Reprinted from King et al. [19], with permission from Elsevier Science, Inc.)... 

In t ie case of animal plasma preparation, an anticoagulant is necessary to maintain solubility of blood components, and sodium citrate or lithium heparin would be preferable over any alternatives that contain EDTA. EDTA will chelate magnesium and zinc ions and require much higher concentrations of the two ions in the assay buffer for acceptable hnal ion concentrations, possibly to the point of precipitation. 

Procedure Starting with 0.2 ml of plasma, prepare a protein-free filtrate by the method of Somogyi (S8). Copenhaver (CIO) has pointed out that the choice of a method for deproteinization which yields an alkaline filtrate is important because of the finding of Wells et al. (W5) that acidic filtrates inhibit trimethylsilylation. 

If plasma or whole blood is required for analysis, then the blood is collected in a tube containing an anticoagulant. Heparin (sodium salt) is frequently used. However, its effect is temporary and heparin is expensive. Therefore, a more widely used anticoagulant is potassium oxalate, about 1 mg per mL blood. Oxalate precipitates blood calcium, and the calcium is required in the clotting process. Obviously, plasma prepared in this way cannot be analyzed for calcium or potassium many other metals are precipitated by oxalate, and so serum is usually analyzed for these. The usual practice in preparing whole blood or plasma samples is to add the required amount of oxalate in solution form to the collection tube and then to dry the tube in an oven at 110°C. By this procedure, the collected blood is not diluted. For example, 0.5 mL of a 2% potassium oxalate solution would be taken and dried for a 10-mL blood sample. Potassium oxalate causes red cells to shrivel, with the result that the intracellular water diffuses into the plasma. Thus, the plasma should be separated as soon as possible. 

Experiments were also conducted using pooled human plasma. The predominant, stable form of the protein in plasma is prothrombin, a zymogen that is cleaved to yield the activated thrombin upon appropriate signaling (Blomback and Hanson, 1979). The presence of any detectable thrombin in its active (i.e., cleaved) form is probably due to stabilizers in the pooled plasma preparation. The plasma concentration of prothrombin is about 90mg/L (Blomback and Hanson, 1979), which corresponds to about 2.5 p.M, or 7.5 pmol on the aptamer spot. 

Although plasma prepared powders could be expected to have interesting applications as ceramic raw materials, little has been published on their sintering characteristics. Experiments conducted using plasma prepared S—AljOj have given disappointing results which can be explained by the removal of grain boundaries... 

One can notice that the reactions are generally completed and that researchers have been mostly concerned with the structure of the plasma-prepared products. As for nitrides, it is possible to divide the experimental techniques into three groups. 

Cousins C.M., HolowniaP., Hawkes J.J., LimayeM.S.,PriceC.P.,KeayP.J., and Coakley W.T., Plasma preparation from whole blood using ultraound. Ultrasound in Medicine and Biology, 26, 881, 2(X)0. 

Table 16.4a shows the quantitative recovery of the rat plasma preparation for the UPLC trace in Figure 16.7. Injected plasma supernatant was quantified with 87.6% of the concentration, 35.9 fmol per milliliter plasma (pA/), of the initial plasma concentration 41 pM, while the precipitated protein pellet contained 13.4% of the original label concentration with 5.5 pM plasma equivalent concentration, showing 100% process retention prior to LC separation. The column recovery of this hydrophobic compound was only 85 6%,... 

Plasma preparation of a dispersed catalyst for hydroconversion of heavy oils... 

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