Abstract：
BACKGROUND:The analysis of red cell folate (RCF) depends on complete hemolysis of erythrocytes, and it is assumed that complete hemolysis is achieved by 10-fold dilution of whole blood with hypotonic solutions of 10 g/L ascorbic acid/ascorbate. This report challenges this assumption. METHODS:The conventional method of erythrocyte lysis was modified to include saponin, a known effective hemolyzing agent. The influence of saponin was determined at various lysate pHs, using the microbiological (Lactobacillus rhamnosus) folate assay. The effect of saponin during lysate preparation was subsequently compared with either the effect of 30 s of sonication or a single 1-h freeze-thaw cycle. RESULTS:Saponin addition was found to increase assayable RCF up to ninefold, depending on lysate pH. Sonication of lysates had no effect, and freezing-thawing lysates once did not always guarantee complete hemolysis. Lysates created with 10 g/L ascorbic acid (a historically widely used diluent) without pH adjustment produced assayable folate concentrations significantly lower than optimal. CONCLUSIONS:A lysing agent should be incorporated into RCF assays to guarantee complete hemolysis. Ten-fold dilution of blood with 10 g/L ascorbic acid, without pH adjustment, produces lysates with pHs (pH 4.0) below the point (pH 4.7) at which hemoglobin can denature irreversibly. The optimum pH for hemolysates is approximately 5.0.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Wright AJ,Finglas PM,Southon Ssubject
Has Abstractpub_date
2000-12-01 00:00:00pages
1978-86issue
12eissn
0009-9147issn
1530-8561journal_volume
46pub_type
杂志文章abstract：:We describe a new double-antibody enzyme radioimmunoassay for thyroxin-binding globulin (TBG) in serum. A TBG-beta-D-galactosidase complex was prepared with m-maleimidobenzoyl N-hydroxysuccinimide ester. The mean analytical recovery of TBG added to serum was 99%, sample volume and TBG value were linearly related, and ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-12-01 00:00:00
abstract：:Values of low-density lipoprotein (LDL) cholesterol (C) according to the Friedewald formula (Clin Chem 1972;18:499-502) were compared with those obtained by lipoprotein fractionation in 98 healthy subjects (control group), 135 specimens from patients with peripheral vascular and cerebrovascular disease (atheroscleroti...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-08-01 00:00:00
abstract：:We developed an enzyme-linked immunosorbent assay (ELISA) system for antibodies to the hepatitis C virus (HCV), using two new recombinant antigens (c11 and c7) derived from the HCV genome. The performance of this ELISA system (Imucheck HCV Ab) was examined. The CV values for both intra-assay precision and reproducibil...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-12-01 00:00:00
abstract：:Comparison of two methods for determining a substance is a common procedure in clinical chemistry. Almost without exception, normal theory statistics are used with the tacit assumption that the data under test show gaussian distributions. Experience has led us to question this assumption for populations of differences...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-03-01 00:00:00
abstract：:We describe a mechanized chromogenic assay for factor X, the results of which correlate well with those for the one-stage clotting assays for factor X in which it is activated either via the extrinsic pathway by thromboplastin or directly by Russell's viper venom. We purified human factor X and raised monospecific ant...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-06-01 00:00:00
abstract：BACKGROUND:PCR-based detection of minimal residual disease (MRD) in neuroblastoma (NB) patients can be used for initial staging and monitoring therapy response in bone marrow (BM) and peripheral blood (PB). PHOX2B has been identified as a sensitive and specific MRD marker; however, its expression varies between tumors....
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.117945
更新日期：2009-07-01 00:00:00
abstract：BACKGROUND:Aberrant DNA hypermethylation of CpG islands occurs frequently throughout the genome in human colorectal cancer (CRC). A genome-wide DNA hypermethylation analysis technique using circulating cell-free DNA (cfDNA) is attractive for the noninvasive early detection of CRC and discrimination between CRC and othe...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2019.301804
更新日期：2019-07-01 00:00:00
abstract：:To produce bispecific antibodies (BiAbs) for enzyme immunoassay (EIA) to replace antibody-enzyme conjugates, we developed a panel of 8-azaguanine/ouabain-resistant anti-urease variant hybridoma cell lines for use in hybridoma-hybridoma fusions. These variants represent mouse immunoglobulin subclasses IgM, IgG1, IgG2a,...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-09-01 00:00:00
abstract：:A simple, direct radioimmunoassay for cortisol in human serum and plasma is described. An antiserum, raised in sheep to a cortisol-3-(O-carboxymethyl)oxime/bovine serum albumin conjugate, is coupled to microcellulose. No extraction is required because plasma samples and standards are incubated with the antiserum and a...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-05-01 00:00:00
abstract：:Owing to increased enzymatic hydrolysis of glutamine, additional ammonia is formed in blood and plasma specimens with increased gamma-glutamyltransferase activity (gamma-GT, EC 2.3.2.2.). The close correlation between gamma-GT and glutaminase (EC 3.5.1.2) activities (r = 0.97) in plasma, the inhibition with 6-diazo-5-...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-08-01 00:00:00
abstract：:Monoclonal antibody CKM-G01 inhibited greater than 99% of the activity of porcine and human creatine kinase(CK)-MM isoenzyme purified from muscle. However, it inhibited only 54% of CK-MM in human serum. Chromatofocusing of serum CK-MM showed that CKM-G01 inhibited 100% of MM3 but not isoform MM1. CKM-G01 inhibited CK-...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-01-01 00:00:00
abstract：BACKGROUND:A substantial proportion of the variability in the absorption and clearance of cyclosporin A (CsA) after oral administration has been attributed to variability in liver cytochrome P-450 3A4 (CYP3A4) activity and intestinal P-glycoprotein (P-gp) concentration. A polymorphism in the CYP3A4 promoter region, ter...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2001-06-01 00:00:00
abstract：:We describe a multiprobe colorimeter that permits the reading of enzyme-linked immunosorbent assays (ELISA) in situ, by use of microhemagglutination plates. The use of dipping probes eliminates interference from meniscus effects and air-bubble entrapment. Detailed validation tests have been done and potential sources ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-04-01 00:00:00
abstract：BACKGROUND:C-Reactive protein (CRP) has been shown to be a strong predictor of coronary heart disease (CHD) and is being considered in cardiovascular disease risk assessment. The number of normolipidemic individuals who are eligible for evaluation of CRP in overall CHD risk assessment is not known. METHODS:We analyzed...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2004.036004
更新日期：2004-09-01 00:00:00
abstract：BACKGROUND:Endothelial nitric oxide synthase (eNOS) could be a candidate gene for coronary artery disease (CAD). This study investigated the relationship of the eNOS Glu(298)-->Asp and T(786)-->C polymorphisms with the presence and severity of CAD in the Italian population. METHODS:We enrolled 415 unrelated individual...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/49.3.389
更新日期：2003-03-01 00:00:00
abstract：BACKGROUND:C-reactive protein (CRP) increases in response to inflammation and is purported to be a risk factor for atherogenesis. We recently demonstrated that a scavenger receptor, lectin-like oxidized LDL receptor (LOX-1), is a receptor for CRP. In light of the overlapping ligand spectrum of scavenger receptors such ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2009.140202
更新日期：2010-03-01 00:00:00
abstract：:An enzymatic, fluorometric method is described for determination of serum urea on silicone-rubber pads. In this method, the reagents are lyophilized on the surface of the pads, NADH on one side and a mixture of urease, glutamate dehydrogenase, and alpha-ketoglutarate on the other. The rate of disappearance of NADH flu...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-01-01 00:00:00
abstract：:We have studied the influence of triglyceride-rich particles on the analytical bias of apolipoprotein B measurements by various immunoturbidimetric methods. Three commercially available methods grossly overestimate apolipoprotein B in samples with even moderately above-normal triglyceride concentrations. This effect i...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-05-01 00:00:00
abstract：:We report the results of a laboratory and clinical evaluation of a commercial kit procedure (Immuno Nuclear Corp.) for measuring the mid-region of the parathyrin molecule. The estimated dose at 50% binding averaged 130 pmol/L, and the minimum detectable concentration was 14 pmol/L. The within-assay CV was less than or...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-11-01 00:00:00
abstract：:In galactosemia, prevention of mental retardation depends on early recognition of the disorder and institution of dietary restriction of galactose. We describe an automated fluorometric micromethod for galactose in whole blood spotted on filter paper. Galactose is oxidized by galactose oxidase to D-galacto-hexadialdos...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-06-01 00:00:00
abstract：:Radioimmunoassays for haloperidol are described, involving use of tritium- or 125I-labeled drug or tritium-labeled spiroperidol, and a rabbit antiserum to a drug/bovine serum albumin conjugate. The 125I-labeled drug was prepared by the Chloramine T iodination technique. A fluoroimmunoassay for haloperidol is also desc...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-07-01 00:00:00
abstract：:We examined the variability of lipid and lipoprotein concentrations in plasma from a population sample from the Jerusalem Lipid Research Clinic study. Coefficients of variation of about 8% for plasma cholesterol, 11% to 15% for low- and high-density-lipoprotein cholesterol, and about 30% for triglyceride were reported...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-07-01 00:00:00
abstract：:We report the adaptation of four radioassays to the prototype of an automated radioimmunoassay system ("Centria," Union Carbide). The system consists of three integrated modules: (a) an automated pipettor, which dispenses samples and reagents; (b) the key module, an incubator/separator, in which centrifugal force is u...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-08-01 00:00:00
abstract：BACKGROUND:The genotype of hepatitis C virus (HCV) is a predictor of antiviral therapeutic response. We describe an approach for HCV genotype determination by real-time PCR and melting curve analysis. METHODS:After automated nucleic acid extraction, we used reverse transcription-PCR in a block cycler to amplify nucleo...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2002-12-01 00:00:00
abstract：:Applying the principles of chemometrics can lead to development of a powerful, simple, comprehensive system for characterizing measurement reliability of analytical processes. The system described here consists of a format for specifications, definitions, and decision rules for evaluating and comparing analytical proc...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-12-01 00:00:00
abstract：:We evaluated the enzymic mechanism by which 3-keto butylidene-beta-2-chloro-4-nitrophenyl maltopentaoside (3KB-G5-CNP) serves as a substrate for serum pancreatic (p-) and salivary (s-) amylases. In aliquots of the reaction mixture, three kinds of beta-2-chloro-4-nitrophenyl oligosaccharides (glucose, maltoside, and ma...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-08-01 00:00:00
abstract：:We describe a new multilayer immunoassay element for the determination of haptens in undiluted serum and plasma. Polysaccharide layers are coated onto a plastic base. The signal layer contains an immobilized antibody and a fluorescent-labeled hapten. A second layer, containing a pigment, acts as an optical screen. Sam...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-09-01 00:00:00
abstract：:We studied the effect of lyophilization of serum pools on the determination of cholesterol with the enzymatic methods used in five automated analyzers: SMAC (Technicon), the RA-1000 (Technicon), the aca (Du Pont), the TDx (Abbott), and the Ektachem 700P (Kodak). We prepared two serum pools: pool A (2.2 g/L) and pool B...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-07-01 00:00:00
abstract：:We analyzed pancreatic enzyme data from 508 patients with suspected pancreatitis by neural network analysis, by an Expert multirule generation protocol, and by receiver-operator characteristic (ROC) curve analysis of a single test result. Neural network analysis showed that use of lipase provided the best means for di...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1993-09-01 00:00:00
abstract：:Organic anions accumulated in blood serum of patients with chronic renal failure were separated by a novel technique: closed-system capillary zone electrophoresis (CZE) in a pH6 carrier-electrolyte system. Hippuric acid (HA), p-hydroxyhippuric acid, and uric acid were identified by their co-elution with standards prep...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-03-01 00:00:00
