Quantification of Antibodies against Factor VIII by an Immunonephelometric Method in a Continuous-Flow System

Author(s):  
F Malagon ◽  
F L Elorza ◽  
E Martin ◽  
A Jimenez

A new immunonephelometric method is described for the quantification of antibodies against factor VIII in sera from patients suffering from haemophilia A. We have been able to reduce the reaction time to only 16 minutes, which permits its application to emergency cases. Applying Spearman's test, we have correlated the results obtained by the immunonephelometric and Ruggieri's methods, obtaining r = 0·87, p<0·01 for n = 11. From the reproducibility studies we obtained SD = 1·16 as maximum dispersion value. Because it is a fully automated method in a continuous-flow system, the possible manual errors are reduced to a minimum; 60 determinations can be carried out in 1 hour.

Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 899
Author(s):  
José Coloma ◽  
Tim Lugtenburg ◽  
Muhammad Afendi ◽  
Mattia Lazzarotto ◽  
Paula Bracco ◽  
...  

Arabidopsis thaliana hydroxynitrile lyase (AtHNL) catalyzes the selective synthesis of (R)-cyanohydrins. This enzyme is unstable under acidic conditions, therefore its immobilization is necessary for the synthesis of enantiopure cyanohydrins. EziG Opal is a controlled porosity glass material for the immobilization of His-tagged enzymes. The immobilization of His6-tagged AtHNL on EziG Opal was optimized for higher enzyme stability and tested for the synthesis of (R)-mandelonitrile in batch and continuous flow systems. AtHNL-EziG Opal achieved 95% of conversion after 30 min of reaction time in batch and it was recycled up to eight times with a final conversion of 80% and excellent enantioselectivity. The EziG Opal carrier catalyzed the racemic background reaction; however, the high enantioselectivity observed in the recycling study demonstrated that this was efficiently suppressed by using citrate/phosphate buffer saturated methyl-tert-butylether (MTBE) pH 5 as reaction medium. The continuous flow system achieved 96% of conversion and excellent enantioselectivity at 0.1 mL min−1. Lower conversion and enantioselectivity were observed at higher flow rates. The specific rate of AtHNL-EziG Opal in flow was 0.26 mol h−1 genzyme−1 at 0.1 mL min−1 and 96% of conversion whereas in batch, the immobilized enzyme displayed a specific rate of 0.51 mol h−1 genzyme−1 after 30 min of reaction time at a similar level of conversion. However, in terms of productivity the continuous flow system proved to be almost four times more productive than the batch approach, displaying a space-time-yield (STY) of 690 molproduct h−1 L−1 genzyme−1 compared to 187 molproduct h−1 L−1 genzyme−1 achieved with the batch system.


2021 ◽  
Vol 140 ◽  
pp. 107769
Author(s):  
Sujka Monika ◽  
Pankiewicz Urszula ◽  
Flisar Karel ◽  
Miklavčič Damijan ◽  
Haberl-Meglič Sasa

Author(s):  
Apisit Naramittanakul ◽  
Supacha Buttranon ◽  
A. Petchsuk ◽  
Pimchai Chaiyen ◽  
Nopphon Weeranoppanant

Immobilization methods have emerged as feasible solutions for increasing the re-usability of biocatalysts, and for simplifying their separation from the desired products. Immobilized biocatalysts can directly be applied to a...


2020 ◽  
Vol 02 (03) ◽  
pp. e128-e132
Author(s):  
Shao-Zheng Guo ◽  
Zhi-Qun Yu ◽  
Wei-Ke Su

AbstractThe development of highly efficient C–C bond formation methods for the synthesis of ethyl 2-(2,4-dichloro-5-fluorobenzoyl)-3-(dimethylamino)acrylate 1 in continuous flow processes has been described, which is based on the concept of rapid and efficient activation of carboxylic acid. 2,4-Dichloro-5-fluorobenzoic acid is rapidly converted into highly reactive 2,4-dichloro-5-fluorobenzoyl chloride by treating with inexpensive and less-toxic solid bis(trichloromethyl)carbonate. And then it rapidly reacts with ethyl 3-(dimethylamino)acrylate to afford the desired 1. This process can be performed under mild conditions. Compared with the traditional tank reactor process, less raw material consumption, higher product yield, less reaction time, higher operation safety ensured by more the environmentally friendly procedure, and process continuity are achieved in the continuous-flow system.


2007 ◽  
Vol 90 (1) ◽  
pp. 85-91 ◽  
Author(s):  
Sung Hyun Kim ◽  
Sang Bum Kim ◽  
Gyung Soo Kim ◽  
Hyun Tae Jang ◽  
Sung Chang Hong

2018 ◽  
Vol 34 ◽  
pp. 02054 ◽  
Author(s):  
N. Idris ◽  
N.A. Lutpi ◽  
Y. S. Wong ◽  
T.N. Tengku Izhar

This research aims to study the acclimatization phase for biohydrogen production from palm oil mill effluent (POME) by adapting the microorganism to the new environment in continuous-flow system of thermophilic bioreactor. The thermophilic fermentation was continuously loaded with 0.4 L/day of raw POME for 35 days to acclimatize the microorganism until a steady state of biohydrogen production was obtained. The significance effect of acclimatization phase on parameter such as pH, microbial growth, chemical oxygen demand (COD), and alkalinity were also studied besides the production of biogas. This study had found that the thermophilic bioreactor reach its steady state with 1960 mL/d of biogas produced, which consist of 894 ppm of hydrogen composition.


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