Single- and coupled-enzyme nylon-tube reactors for plasma glucose determination with glucose oxidase and aldehyde dehydrogenase.

1980 ◽  
Vol 26 (12) ◽  
pp. 1652-1655 ◽  
Author(s):  
W Hinsch ◽  
A Antonijewić ◽  
P V Sundaram

Abstract We describe routine methods for determining glucose in plasma with use of aldehyde dehydrogenase or glucose oxidase-aldehyde dehydrogenase immobilized in a nylon tube that is integrated into a continuous-flow system. Although the coupled-enzyme nylon-tube reactors require the presence of a third enzyme, catalase, in solution, the kinetics are not so complicated as to preclude reliable routine determination of glucose at very low cost. Precision is good, and results correlate well with those by the method involving glucose oxidase in solution. More than 3000 tests may be carried out with one reactor. The immobilized enzymes are stable for several months at 4 degrees C when not in use.

1979 ◽  
Vol 25 (2) ◽  
pp. 285-288 ◽  
Author(s):  
P V Sundaram ◽  
W Hinsch

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.


Author(s):  
C. E. Wilde ◽  
P. Sewell

A continuous flow system for the determination of glucose in blood or plasma using glucose oxidase is described. Oxygen uptake is measured by a Clarke electrode linked through an oxygen monitor and pH meter to a recorder. The omission of a peroxidase-chromogen step increases the specificity of the assay which gives very good correlation with the hexokinase-NADPH method. The system has a high sensitivity which can be adjusted by changing the oxygen-nitrogen ratio of the segmenting gas. It is useful when measuring ‘true glucose’ in low concentration and gives a linear response within the range 0 to 200 mg/100 ml. The electrode response time limits the rate of analysis to 30 samples per hour if adequate precision is to be maintained. The advantages of a closed continuous flow system over manual electrometric methods are discussed.


1974 ◽  
Vol 137 (1) ◽  
pp. 25-32 ◽  
Author(s):  
D. J. Inman ◽  
W. E. Hornby

1. Glucose oxidase (EC 1.1.3.4), amyloglucosidase (EC 3.2.1.3), invertase (EC 3.2.1.26) and β-galactosidase (EC 3.2.1.23) were covalently attached via glutaraldehyde to the inside surface of nylon tube. 2. The linked enzyme system, comprising invertase immobilized within a nylon tube acting in series with glucose oxidase immobilized in a similar way, was used for the automated determination of sucrose. 3. The linked enzyme system, comprising β-galactosidase immobilized within a nylon tube acting in series with glucose oxidase immobilized in a similar way, was used for the automated determination of lactose. 4. The linked enzyme system, comprising amyloglucosidase immobilized within a nylon tube acting in series with glucose oxidase immobilized in a similar way, was used for the automated determination of maltose. 5. Mixtures of glucose oxidase and amyloglucosidase were immobilized within the same piece of nylon tube and used for the automated determination of maltose. 6. Mixtures of glucose oxidase and invertase were immobilized within the same piece of nylon tube and used for the automated determination of sucrose.


1984 ◽  
Vol 67 (1) ◽  
pp. 108-111
Author(s):  
Fred M Gretch ◽  
Joseph D Rosen

Abstract An automated continuous flow procedure is described that improves the cost effectiveness and precision of AOAC methodology for multiresidue pesticide determinations in nonfatty foods. Individual modules capable of performing automated solvent partitioning and automated column chromatography were constructed and integrated into a continuous flow system. Data are presented comparing the recoveries and precision for the determination of 8 pesticides (aldrin, dieldrin, p,p’ - DDT, ethion, heptachlor epoxide, lindane, parathion, and ronnel) partitioned from 2 food crops (spinach and tomatoes) by both the manual and automated procedures.


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