Whole blood samples

Changes in the reference electrode junction potential result from differences in the composition of die sample and standard solutions (e.g., upon switching from whole blood samples to aqueous calibrants). One approach to alleviate this problem is to use an intermediate salt bridge, with a solution (in the bridge) of ions of nearly equal mobility (e.g., concentrated KC1). Standard solutions with an electrolyte composition similar to that of the sample are also desirable. These precautions, however, will not eliminate the problem completely. Other approaches to address this and other changes in the cell constant have been reviewed (13). 

Qmntitatlvz detznmivuition oi HzmogtobZn Ai by micAjochAo-matogAaphy - By means of this simple method (29, 30), Hb-A2 may be rapidly and accurately determined In blood samples from subjects with and without Hb-S or Hb-D The procedure makes use of DEAE-Cellulose, Inexpensive laboratory glassware, and allows one technician to determine the level of Hb-A2 In 50 samples a day Whole blood samples, red cell hemolysates, and blood... 

The present state of the art in blood pH measurements allows for rapid (1 minute) determination of pH between 6.4 and 8.0 to within at least 0.005 units for whole blood sample volumes < 100 microliters. The temperature of the electrodes and sample is generally controlled to within 0.1 °C for this level of precision and frequent calibration is carried out (in some cases a one point calibration for each sample). The electrodes require (both the glass and external reference) some maintenance due to protein fouling, however this procedure is largely automated. The useful life of an electrode is one year or less and the cost is well over 100 (U.S.) each. New technologies, both electrochemical and non-electrochemical, must compete with this attractive performance and provide for lower operating costs in order to be successful. 

Purrott et al. (1980) used a method similar to DuFrain et al.. see above. They added Pu-239 and Am-241 nitrate solutions to agitated whole blood samples. A linear dose relationship was observed over the dose range of 0.13 to 1.6 Gy and the RBE compared to Co-60 gamma rays was 4 8. 

Galvanostatically pulsed sensors can be employed for heparin determination via titration with protamine using protocol described earlier [42, 43] and initial experiments showed that heparin detection in whole blood samples can be accomplished with this technology. 

T.K. Lim, H. Ohta, and T. Matsunaga, Microfabricated on-chip-type electrochemical flow immunoassay system for the detection of histamine released in whole blood samples. Anal. Chem. 75, 3316-3321 (2003). 

Koal et al. (2004) measured four immunosuppressants (cyclosporine A, tacrolimus, sirolimus, and everolimus) in whole blood samples from transplant recipients. The samples were treated first with a protein precipitation step. The supernatant was extracted with a Poros Rl/20 perfusion column (30 x 2.1 mm, 20 tm, Applied Biosystems, Darmstadt, Germany) online. A Luna phenyl hexyl column (2 x 50 mm, Phenomenex, Schaffenburg, Germany) was used for separation. The total run time was 2.5 min. The lower limit of quantitation was 10 ng/mL for cyclosporine A and 1 ng/mL for the other three analytes. 

The calibration curve was linear up to 5000 /tg/mL. Recoveries for cyclosporine ranged from 90 to 110 %. The limit of detection was below 30 /.ig/mE. Within-run and between-run coefficients of variation were less than 8%. About 100 whole blood samples could be analyzed within 3 hr with very high efficiency, sensitivity, and precision. 

Blank, calibrator, control, and patient whole-blood samples (50 /iL) were transferred into 1.5 mL conical test tubes, mixed with 100 /xL of the IS, vortexed for 10 sec, and centrifuged at 13,000 g for 5 min. Twenty-five microliters of supernatant were injected onto a Cohesive Technologies Cyclone polymeric turbulent flow column (50 x 1 mm, 50 /flushed with a mixture of methanol and water (10 90 v/v) at a flow of 5 mL/min. Column switching from the TFC to HPLC systems was via a Cohesive Technologies system. The analytical column was a Phenomenex Phenyl-Hexyl-RP (50 x 2.1 mm, 5 /.mi). The mobile phase consisted of methanol and ammonium acetate buffer (97 3 v/v). The buffer was 10mM ammonium acetate containing 0.1% v/v acetic acid. The flow rate was 0.6 mL/min. 

Heptachlor epoxide was found in whole blood samples from nonoccupationally exposed mothers and their newborns in Argentina (Radomski et al. 1971a). The average level of heptachlor epoxide was 0.23 0.29 ppb in 13 mothers and 0.06 0.01 ppb in 13 newborn infants, although no blood samples were taken from the mothers during pregnancy (Radomski et al. 1971a). 

Fig. 2. Forward vs right-angle light-scatter profiles of granulocytes in an erythrocyte-lysed, whole-blood sample (A) and a purified granulocyte preparation (B).

Zhang T, Wu Q, Sun WFI, Rao J, Kannan K (2010) Perchlorate and iodide in whole blood samples from infants, children, and adults in Nanchang, China. Environ Sci Technol... 

Herrin, G., McCurdy, H.H.H. and Wall, W.H. (2005) Investigation of an LCMSMS (QTrap) Method for the Rapid Screening and Identification of Drugs in Postmortem Toxicology Whole Blood Samples. J Anal Toxicol, 29, 599. 

Inhibition of COX can be quantified in recombinant or natural enzyme preparations, cellular systems, isolated human cell populations such as platelets (COX-1) and white blood cells (COX-2), or in ex vivo stimulated whole blood samples The closer the experimental system is to the physiological state, the lower the selectivity for most COX-2-inhibitors. The standard test for comparison is considered to be a whole blood assay which mimics in vivo conditions like plasma binding (e.g. Patrignani et al., 1996). It is commonly accepted that reasonable variations occur between different laboratories (see data for Piroxicam). Therefore, whenever possible, data of several compounds generated with a given test system should be compared with each other. 

Kim YJ, Hahn S, Yoon G. Determination of glucose in whole blood samples by mid-infrared spectroscopy. Applied Optics 2003, 42, 745-749. 

Papke O, Ball M, Lis ZA, et al. 1989b. PCDD/PCDF in whole blood samples of unexposed persons. Chemosphere 19 941-948. 

The slit-type filter has also been used for cell retention. For instance, a porous filter has been used to retain rabbit blood cells in a whole blood sample. This filter was fabricated inside a glass microchannel using emulsion photopolymerization. The retained cells were then lysed for the assay of G-6-PDH [832],... 

Though human error is usually the cause, proper method development can make a difference in reducing this type of error or variations. First, a large volume of IS, such as 200 pL should be used when it is added by a repeater pipette because small volumes (such as 50 pL or less) are more prone to imprecision than large ones. In addition, it would be extremely difficult to visually spot missed or doubled addition for an internal standard when its volume is much smaller than that of samples and/ or other reagents (e.g., buffer). Second, it would be helpful to reduce errors by adding the usually colorless IS solution first and then incurred samples, which are usually colored, such as slight yellowish for plasma samples or dark red for whole blood samples. 

Experiment. Prepare test whole blood QC pools at medium QC level. Store at room temperature and 5 °C for 0 (control), 1 and 2 h. Centrifuge the whole blood sample and collect the plasma (test matrix) for extraction and analysis following the validation method. Analyze six (6) replicates for each group. Compare the mean instrument response of stability test samples to that of the control group. 

Fig. 1 Using a T-piece between HPLC and MS, a syringe pump can be utilized to infuse a constant flow of analytes at therapeutic concentrations whilst drug spiked whole blood samples are delivered via SPE-HPLC. Ion traces of the analytes (here everolimus at 6 ng/ml) are recorded. In this particular case, no ion yield attenuation due to the spiked drug can be observed, although strong effects can be seen in the solvent front elution zone shortly prior to the analyte elution time window...

In an in vitro study, whole blood samples were spiked with water-soluble chromium(VI) or chromium(III) compounds. The results showed a greater level of chromium inside erythrocytes after treatment with chromium(VI) compounds, compared to chromium(III) compounds. The investigators reported that both chromium(VI) and chromium(III) compounds permeated the cell membrane, but only chromium(VI) compounds are taken up by erythrocytes and form complexes with intracellular proteins that could not be eliminated (Lewalter et al. 1985). 

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