scholarly journals Comparative evaluation of three assay systems for automated determination of hemoglobin A1c

1997 ◽  
Vol 43 (3) ◽  
pp. 511-517 ◽  
Author(s):  
Gabriele Halwachs-Baumann ◽  
Susanne Katzensteiner ◽  
Wolfgang Schnedl ◽  
Peter Pürstner ◽  
Thomas Pieber ◽  
...  
Keyword(s):  
Clinical Laboratory ◽  
Chronic Hemodialysis ◽  
Good Precision ◽  
Hb A1c ◽  
Hemoglobin Variants ◽  
Good Concordance ◽  
Routine Clinical Laboratory ◽  
Interference Study ◽  
Automated Determination

Abstract We evaluated three newly introduced systems for automated determinations of hemoglobin (Hb) A1c, which allow the processing of large amounts of samples in a routine clinical laboratory. We compared these methods—the Variant HPLC, the Hi-Auto A1c analyzer system, and the Roche immunoassay—with the Diamat HPLC system. All showed good precision and good concordance with the Diamat HPLC. The reference range for Hb A1c has to be determined by the laboratory for each assay system. Interference study showed no statistically significant influence of anemia, polycythemia, rheumatoid factor, or chronic hemodialysis, although individual Hb A1c values can be influenced by polycythemia (when measured with the Hi-Auto A1c analyzer) and by chronic hemodialysis (when measured with the Variant HPLC). HPLC was not suitable for measuring Hb A1c in the examined cases of hemoglobin variants; assaying fructosamine seems to be better for monitoring these patients.

Adaptation of Babson's Method for the Determination of Serum Glutamic Oxalacetic Transaminase in the Clinical Laboratory

1965 ◽  
Vol 11 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Masaki Furuno ◽  
Albert Sheena
Keyword(s):  
Clinical Laboratory ◽  
Glutamic Oxalacetic Transaminase ◽  
Laboratory Workers ◽  
Routine Clinical Laboratory ◽  
Serum Glutamic Oxalacetic Transaminase ◽  
Final Color

Abstract Babson's method for the assay of serum glutamic oxalacetic transaminase (SGO-T) is modified to increase its accuracy and reliability. The final color produced is made stable with the addition of bisulfite ion, thereby making the procedure more suitable for the routine clinical laboratory. The 95% limits for values on 20 healthy laboratory workers was 4 to 26 units with a mean of 13 units.

Direct analysis for urinary protein with biuret reagent, with use of urine ultrafiltrate blanking: comparison with a manual biuret method involving trichloroacetic acid precipitation.

1984 ◽  
Vol 30 (3) ◽  
pp. 443-446 ◽  
Author(s):  
J H Eckfeldt ◽  
M J Kershaw ◽  
I I Dahl
Keyword(s):  
Trichloroacetic Acid ◽  
Clinical Laboratory ◽  
Acid Precipitation ◽  
Direct Analysis ◽  
Urinary Protein ◽  
New Method ◽  
Good Precision ◽  
Manual Method ◽  
Biuret Method ◽  
Routine Clinical Laboratory

Abstract We describe a method for measuring urinary protein with a centrifugal analyzer. Biuret reagent is used, and blanking with an ultrafiltrate of urine eliminates interferences from the nonprotein, biuret-positive chromogens in urine. We compare results by this new method with those by a manual method in which trichloroacetic acid precipitation and biuret reagent are used. The new method shows good precision and excellent correlation (r = 0.997) with the manual method. The ease and convenience of this assay should make this a useful method for the routine clinical laboratory.

Microencapsulated antibodies in radioimmunoassay--I. Determination of digoxin.

1979 ◽  
Vol 25 (6) ◽  
pp. 860-862 ◽  
Author(s):  
E P Halpern ◽  
R W Bordens
Keyword(s):  
Interfacial Polymerization ◽  
Clinical Laboratory ◽  
Rabbit Antibody ◽  
Nylon Membrane ◽  
Antibody Technique ◽  
Standard Curve ◽  
Analytical Recovery ◽  
Routine Clinical Laboratory ◽  
Toxic Concentrations

Abstract We describe the application of the microencapsulated-antibody technique to the radioimmunoassay of digoxin in serum. Droplets of emulsified rabbit antibody are microencapsulated in a semipermeable nylon membrane by an interfacial polymerization technique. The antibody microcapsules are incubated with 125I-labeled digoxin and unlabeled digoxin for 15 min at 37 degrees C, then free and bound digoxin are separated by centrifugation. Subtherapeutic, therapeutic, and toxic concentrations of digoxin in sera can be determined, with use of a standard curve prepared by use of known amounts of digoxin. With this technique we obtained an intra-laboratory correlation coefficient of 0.945 for 100 patients' sera and one of 0.940 for interlaboratory results for 21 sera (10 laboratories) when compared to a routine clinical laboratory radioimmunoassay for digoxin. Icterus, lipemia, hemoglobin, or disproteinemia had no effect on the analytical recovery of digoxin. The standard curve was linear to 6 microgram/L; the sensitivity was 0.25 microgram/L.

scholarly journals Capillary electrophoresis system for hemoglobin A1c determinations evaluated

1997 ◽  
Vol 43 (4) ◽  
pp. 644-648 ◽  
Author(s):  
Cees J A Doelman ◽  
Carla W M Siebelder ◽  
Wim A Nijhof ◽  
Cas W Weykamp ◽  
Jacques Janssens ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Hemoglobin A1c ◽  
Clinical Laboratory ◽  
Analytical Tool ◽  
Analytical Technique ◽  
Hb A1c ◽  
Patients With Diabetes ◽  
Hb S ◽  
Electrophoresis System ◽  
Hemoglobin Variants

Abstract Hb A1c is the analyte of choice for monitoring metabolic control in patients with diabetes mellitus. Here we present a new analytical technique for measuring Hb A1c, capillary electrophoresis. The Hb A1c determination is not influenced by the labile Hb A1c fraction or by carbamylated or acetylated hemoglobin derivatives. Also, hemoglobin variants (Hb F, Hb S, and Hb C) do not interfere. This new application of capillary electrophoresis seems to be a valuable analytical tool for measuring Hb A1c in the clinical laboratory.

Single- and coupled-enzyme nylon tube reactors for routine determination of pyruvate and lactate in serum.

1979 ◽  
Vol 25 (2) ◽  
pp. 285-288 ◽  
Author(s):  
P V Sundaram ◽  
W Hinsch
Keyword(s):  
Lactate Dehydrogenase ◽  
Continuous Flow ◽  
Clinical Laboratory ◽  
Low Cost ◽  
Serum Lactate ◽  
Tube Reactor ◽  
Nylon Tube ◽  
Lactate And Pyruvate ◽  
Routine Clinical Laboratory

Abstract We describe the use of a continuous-flow clinical analyzer with an immobilized coupled-enzyme nylon tube reactor and an immobilized single-enzyme nylon tube reactor for routine estimation of lactate and pyruvate in serum. These reactors are incorporated into the flow system of a modified continuous-flow analyzer (Technicon AutoAnalyzer). Results for serum lactate and pyruvate by this method are compared with those by corresponding methods in which the same enzymes are used in solution, either automatically (pyruvate) or manually (lactate) performed. Routine clinical laboratory determinations with use of the coupled-enzyme system lactate dehydrogenase and alanine aminotransferase, co-immobilized in the nylon tube reactor for estimation of lactate, and lactate dehydrogenase reactors for estimation of pyruvate give reliable and reproducible results with high precision at low cost.

scholarly journals Sensitive Sandwich Enzyme Immunoassay for Serum Ferritin on Microtitre Plates

1981 ◽  
Vol 18 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Sukanya Linpisarn ◽  
Larry J Kricka ◽  
John H Kennedy ◽  
Thomas P Whitehead
Keyword(s):  
Enzyme Immunoassay ◽  
Serum Ferritin ◽  
Clinical Laboratory ◽  
Solid Phase ◽  
Good Precision ◽  
Ferritin Concentration ◽  
Assay Procedure ◽  
Serum Ferritin Concentration ◽  
Sandwich Enzyme Immunoassay

A solid-phase sandwich enzyme immunoassay for serum ferritin is described. The assay procedure was simple, showed good precision, and was suitable for the routine determination of serum ferritin concentration in a clinical laboratory. The assay compared well with a conventional radioimmunoassay for ferritin. The assay was extremely sensitive and had a detection limit of 2·2 pg.

Simplified Benzophenone Procedure for Determination of Diphenylhydantoin in Plasma

1971 ◽  
Vol 17 (12) ◽  
pp. 1200-1201 ◽  
Author(s):  
Wesley A Dill ◽  
Lucy Chucot ◽  
Tsun Chang ◽  
Anthony J Glazko
Keyword(s):  
Oxidation Product ◽  
Clinical Laboratory ◽  
Ethylene Dichloride ◽  
Routine Clinical Laboratory ◽  
The Cost ◽  
Distillation Equipment

Abstract Diphenylhydantoin (DPH) is extracted from plasma with ethylene dichloride, returned to alkali, and oxidized with permanganate in glass-stoppered test tubes containing a layer of iso-octane. The absorbance of the oxidation product (benzophenone) in the iso-octane layer is measured spectrophotometrically. This procedure eliminates interference by chloroform that is encountered in other methods; highly specialized reflux condensers or distillation equipment is not needed; and the cost of solvents is decreased. The procedure is highly specific; it detects less than 1 µg of DPH per milliliter of plasma, and it is suitable for routine clinical laboratory use.

Phenolphthalein Monophosphate as a Substrate for Serum Alkaline Phosphatase

1966 ◽  
Vol 12 (10) ◽  
pp. 701-708 ◽  
Author(s):  
J H Wilkinson ◽  
Ann V Vodden
Keyword(s):  
Alkaline Phosphatase ◽  
Serum Concentration ◽  
Inorganic Phosphate ◽  
Clinical Laboratory ◽  
Serum Alkaline Phosphatase ◽  
Routine Procedure ◽  
Laboratory Conditions ◽  
Straight Line ◽  
Routine Clinical Laboratory

Abstract The procedure for serum alkaline phosphatase determination employing phenolphthalein monophosphate as substrate was evaluated under routine clinical laboratory conditions. A straight-line response to increasing serum concentration was observed, and the reaction was shown to be Mg++ dependent. The method proved to be extremely simple, and the results obtained correlated well with those given by a standard routine procedure involving determination of the liberated inorganic phosphate.

Determination of plasma and erythrocyte lithium concentrations by atomic absorption spectrophotometry.

1977 ◽  
Vol 23 (1) ◽  
pp. 41-45 ◽  
Author(s):  
G H Hisayasu ◽  
J L Cohen ◽  
R W Nelson
Keyword(s):  
Atomic Absorption ◽  
Whole Blood ◽  
Room Temperature ◽  
Clinical Laboratory ◽  
Lithium Concentration ◽  
Atomic Absorption Spectrophotometry ◽  
Laboratory Procedure ◽  
Absorption Spectrophotometry ◽  
Routine Clinical Laboratory

Abstract We describe a method for determining plasma and erythrocyte lithium concentrations by atomic absorption spectrophotometry. Plasma and hemolyzed whole-blood are diluted and analyzed, with use of a lithium hollow-cathode lamp, at 670.8 nm. Erythrocyte lithium concentrations are calculated indirectly from the hematocrit. The standard deviation for a 0.43 mmol/liter pool of whole blood, run daily over 11 months, was +/-20 mumol/liter (CV=5.1). The lithium concentration of a lyophilized pool assayed periodically over the same period (n=127) was 1.84+/-0.05 mmol/liter (CV=2.7%). The relatively low erythrocyte/plasma lithium ratio and the microhematocrit centrifugation force (9600 to 13 600 X g) make corrections for trapped plasma insignificant. Problems with matrix matching and viscosity are overcome by using a plasma pool standard for calculations. Values for erythrocyte lithium concentrations were unchanged in samples stored at room temperature up to 24 h. Hemolysis appears to be of possible clinical significance. This method is useful as a routine clinical laboratory procedure for monitoring patients with affective disorders, who are undergoing therapy with lithium.

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