Kits for enzyme determinations compared: relation between composition and quality.

1984 ◽  
Vol 30 (10) ◽  
pp. 1625-1630
Author(s):  
F P Peters ◽  
J C Hafkenscheid

Abstract Kits of five different suppliers, composed according to the Dutch recommendations for determination of the enzyme activity of alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, gamma-glutamyltransferase, alkaline phosphatase, and creatine kinase, were intercompared. Activity concentrations of the enzymes in human sera were measured under defined conditions, evaluated, and related to the actual composition of the kits. Concentrations of all kit components were determined by various analytical techniques. The overall results of the activity measurements and the composition of at least three kits inter-agree well. We found deviations as great as 10% in our analytical evaluation of the kits of the other two suppliers, which can partly be accounted for.

1984 ◽  
Vol 30 (3) ◽  
pp. 364-368 ◽  
Author(s):  
M K Schwartz ◽  
B E Statland ◽  
J Coughlin ◽  
C Eisen ◽  
M Fleisher ◽  
...  

Abstract In the RA-1000, a random-access discrete analyzer, an inert fluorocarbon fluid is used to prevent interaction and carryover. Production-model instruments were evaluated in two laboratories with respect to determination of glucose, creatinine, total protein, inorganic phosphorus, cholesterol, alkaline phosphatase, lactate dehydrogenase, creatine kinase, gamma-glutamyltransferase, and aspartate and alanine aminotransferases. Within-run, among-run, and day-to-day (for 15 days) precision was assessed, and results were correlated with those obtained by the methods routinely in use in our departments. Precision was excellent, correlation acceptable.


1987 ◽  
Vol 33 (10) ◽  
pp. 1911-1913 ◽  
Author(s):  
R H Ng ◽  
M Altaffer ◽  
M O'Neill ◽  
H Mukadam ◽  
B E Statland

Abstract We evaluated the performance of the Kodak DTSC Module for determination of alanine aminotransferase (ALT; EC 2.6.1.2), aspartate aminotransferase (2.5.1.2), alkaline phosphatase (3.1.3.1), creatine kinase (2.7.3.2), gamma-glutamyltransferase (2.3.2.2), and lactate dehydrogenase (1.1.1.27). The DTSC is a "special chemistry" accessory for the DT60 analyzer; the same multilayer film technology as that of the Ektachem 700 is used. The overall precision, assessed over a three-month period with two serum-based quality control materials, ranged from 2.2 to 8.0%. DTSC results for patients' specimens correlated well with those by the Technicon RA-1000 analyzer. The performance of the analyzer in linearity and interference studies was satisfactory for clinical use. The DTSC is simple to operate and has no technique-dependent step; it should be useful for the physician's office laboratory.


1985 ◽  
Vol 31 (9) ◽  
pp. 1506-1508 ◽  
Author(s):  
A Truchaud ◽  
G Glikmanas ◽  
Y Gourmelin ◽  
J Hersant ◽  
D Trepo ◽  
...  

Abstract In the disposable rotor of the SAM microcentrifugal analyzer, various lyophilized reagents are predistributed in 24 33-microL cuvets, for determination of multiple analytes in one specimen (e.g., for patient profiles). We evaluated a prototype of this system, which can be used at 25, 30, or 37 degrees C; absorbance readings at 340, 405, and 500 nm varied linearly up to 2.0 A. Starting the reactions by rehydrating the reagents with diluted serum is adequate because absorbance readings do not begin until 180 s after initiating the rehydration. Analytical performances of kinetic determinations at 30 degrees C showed good accuracy and correlation with other methods for creatine kinase, amylase, aspartate aminotransferase, and gamma-glutamyltransferase. Kinetic determinations for urea, and equilibrium determinations with blank corrections for glucose, cholesterol, and triglycerides gave excellent results for glucose and correct results for the other analytes. This compact analyzer combines the analytical performances of a centrifugal analyzer with the practicability of instruments having predistributed reagents.


1977 ◽  
Vol 23 (11) ◽  
pp. 2034-2038 ◽  
Author(s):  
N K Kim ◽  
W G Yasmineh ◽  
E F Freier ◽  
A I Goldman ◽  
A Theologides

Abstract We assessed, in 98 patients with cancer, the diagnostic value of measuring serum alkaline phosphatase, 5'-nucleotidase, gamma-glutamyltransferase, and glutamate dehydrogenase activities as an aid to detection of liver metastases. All four enzymes showed diagnostic value, but 5'-nucleotidase appeared to have the greatest. It showed the lowest false-positive results (7.4%) with the highest predictive value of a positive test (85.7%) and agreement (81.3%).. gamma-Glutamyltransferase showed the lowest proportion of false-negative results (2.8%), but was the least specific 35% false-positive results). Analysis of various test combinations showed that the best agreement (77.5%) was obtained when the patients were divided into those who had no or only one abnormal test result, and those who had two or more abnormal test results. However, this was not better than the agreement for 5' nucleotidase alone (81.3%). The agreement of 5'-nucleotidase and gamma-glutamyltransferase (i.e., both tests were positive or negative) was excellent (91.4%), but such agreement included only 67% of the patients with liver metastases.


1980 ◽  
Vol 26 (2) ◽  
pp. 297-300
Author(s):  
K Bauer ◽  
P M Bayer ◽  
E Deutsch ◽  
F Gabl

Abstract We describe a simple method for detecting enzyme--immunoglobulin G (IgG) complexes in human serum. Protein-A Sepharose CL-4B binds IgG and therefore also the enzyme--IgG complexes, which can then be separated easily from the serum by centrifugation. We demonstrate this separation in two patients, one with a complex of IgG and creatine kinase (EC 2.7.3.2) BB isoenzyme, the other with an IgG--alkaline phosphatase (EC 3.1.3.1) complex. Both patients had unexplainably high activities of the respective enzymes in their serum. The method we propose should be a useful, simple, routine method of detection in cases where IgG--enzyme complexes are suspected.


1986 ◽  
Vol 32 (1) ◽  
pp. 165-169
Author(s):  
G C Moses ◽  
G O Lightle ◽  
J F Tuckerman ◽  
A R Henderson

Abstract We evaluated the analytical performance of the EPOS (Eppendorf Patient Oriented System) Automated Selective Chemistry Analyzer, using the following tests for serum analytes: alanine and aspartate aminotransferases, lactate dehydrogenase, creatine kinase, gamma-glutamyltransferase, alkaline phosphatase, and glucose. Results from the EPOS correlated well with those from comparison instruments (r greater than or equal to 0.990). Precision and linearity limits were excellent for all tests; linearity of the optical and pipetting systems was satisfactory. Reagent carryover was negligible. Sample-to-sample carryover was less than 1% for all tests, but only lactate dehydrogenase was less than the manufacturer's specified 0.5%. Volumes aspirated and dispensed by the sample and reagent II pipetting systems differed significantly from preset values, especially at lower settings; the reagent I system was satisfactory at all volumes tested. Minimal daily maintenance and an external data-reduction system make the EPOS a practical alternative to other bench-top chemistry analyzers.


2012 ◽  
Vol 10 (3) ◽  
pp. 675-685 ◽  
Author(s):  
Sezgin Bakırdere ◽  
Selin Bora ◽  
E. Bakırdere ◽  
Fırat Aydın ◽  
Yasin Arslan ◽  
...  

AbstractCarcinogenic and mutagenic properties of aflatoxin species are known in literature. Their intake over a long time period might be health-dangerous for human even at trace levels. It is well known that different foodstuffs can be contaminated by aflatoxin species through growing and storage. Due to the serious health effects, sensitive determination of aflatoxin species in any matrices related with the human being is very crucial at trace levels. In literature, there are sensitive techniques to analyze the different samples for the contents of their aflatoxin species. Each technique has some advantages and disadvantages over the other techniques. This review aims to summarize the different health effects of aflatoxin species, development of analytical techniques and applications of developed techniques in a variety of matrices.


Author(s):  
G. Schumann ◽  
R. Aoki ◽  
C.A. Ferrero ◽  
G. Ehlers ◽  
G. Férard ◽  
...  

AbstractThis paper is the eighth in a series dealing with reference procedures for the measurement of catalytic activity concentrations of enzymes at 37°C and the certification of reference preparations. Other parts deal with: Part 1. The concept of reference procedures for the measurement of catalytic activity concentrations of enzymes; Part 2. Reference procedure for the measurement of catalytic concentration of creatine kinase; Part 3. Reference procedure for the measurement of catalytic concentration of lactate dehydrogenase; Part 4. Reference procedure for the measurement of catalytic concentration of alanine aminotransferase Part 5. Reference procedure for the measurement of catalytic concentration of aspartate aminotransferase Part 6. Reference procedure for the measurement of catalytic concentration of γ-glutamyltransferase; Part 7. Certification of four reference materials for the determination of enzymatic activity of γ-glutamyltransferase, lactate dehydrogenase, alanine aminotransferase and creatine kinase at 37°C. The procedure described here is deduced from the previously described 30°C IFCC reference method. Differences are tabulated and commented on.Clin Chem Lab Med 2006;44:1146–55.


1980 ◽  
Vol 26 (6) ◽  
pp. 707-711 ◽  
Author(s):  
T D Schlabach ◽  
J A Fulton ◽  
P B Mockridge ◽  
E C Toren

Abstract We observed nonenzymic peaks when serum isoenzymes of lactate dehydrogenase (EC 1.1.1.27; LD) and creatine kinase (EC 2.7.3.2.; CK) were separated by “high-performance” liquid chromatography and detected by continuously monitoring the column effluent for enzyme activity. Such background peaks were particularly apparent in CK isoenzyme profiles obtained from human sera. We observed two nonenzymic peaks with fluorescence detection, one in the CK-MB region, the other in the CK-BB region. Serum albumin was a major component in the artifactual CK-MB peak, with lipoprotein as a minor component. We present evidence that the material responsible for the other peak fluoresced quite strongly and is mostly pre-albumin.


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