Method for Monitoring A Reaction, And Reaction System For Implementing Same

Abstract

The invention relates to a method for monitoring a reaction and to a reaction system which are inexpensive, compact, easy to implement, and enable the reaction medium to be fully supervised throughout the entire experiment. For this purpose, the invention relates to a reaction system, in particular for microorganism cultures, including: at least one vessel (M 1 ) for the reaction medium ( 1, 1′ ), which is in fluid communication with an injection tube ( 10 ); at least one vessel (F 1 ) for a carrier fluid ( 11 ) that is immiscible with the reaction medium ( 1, 1′ ), which is in fluid communication with a reaction tube ( 20 ); the injection tube ( 10 ) being mounted so as to lead into the reaction tube ( 20 ) such that individual drops ( 30 ) of the reaction medium can be injected into the reaction tube ( 20 ) and into the immiscible carrier fluid ( 11 ), so as to form a train of reaction chambers; at least one detector for monitoring a reaction; a means for classifying the reaction chambers; and at least one means for recirculating reaction chambers in front of at least one detector for monitoring a reaction.

1 . A reaction system, notably of cultures of microorganisms, comprising:
 at least one reservoir of reaction mixture fluidically connected to a capillary injection tube;   at least one reservoir of a carrier fluid that is immiscible with the reaction mixture, fluidically connected to a capillary reaction tube,   the capillary injection tube being mounted opening into the capillary reaction tube so that individual drops of reaction mixture are injectable into the capillary reaction tube, into the immiscible carrier fluid, so as to form a succession of reactors,   at least one reaction monitoring detector,   wherein the system comprises a means of referencing the reactors for identifying them uniquely in the succession of reactors, and at least one means for recirculating the reactors in front of at least one reaction monitoring detector.   
     
     
         2 . The reaction system as claimed in  claim 1 , in which the recirculating means comprises a loop for recirculating the reactors in front of the detector or detectors, said recirculating loop comprising a capillary discharging upstream and downstream of the detector or detectors. 
     
     
         3 . The reaction system as claimed in  claim 1 , in which the recirculating means comprises a recirculating means able to reverse the direction of circulation of the reactors. 
     
     
         4 . The reaction system as claimed in  claim 1 , for culturing microorganisms, in which the reaction mixture is a medium for culturing microorganisms, the capillary reaction tube is a capillary culture tube, and the reactors are reactors for culture of microorganisms. 
     
     
         5 . The reaction system as claimed in  claim 1 , further comprising at least one reservoir of a separating fluid that is immiscible with the carrier fluid and immiscible with the reaction mixture, fluidically connected to the capillary reaction tube so that drops of separating fluid can be injected into the carrier fluid between two reactors. 
     
     
         6 . The reaction system as claimed in  claim 1 , further comprising at least one reservoir of reagent fluidically connected to the capillary injection tube and/or to the capillary reaction tube, so that reagent can be mixed with the reaction mixture. 
     
     
         7 . The reaction system as claimed in  claim 5 , in which the carrier fluid and the separating fluid are mutually immiscible oils, the reaction mixture being an aqueous medium that is immiscible with the aforementioned oils. 
     
     
         8 . The reaction system as claimed in  claim 1 , further comprising at least one waste reservoir connected fluidically to the capillary reaction tube. 
     
     
         9 . The reaction system as claimed in  claim 1 , further comprising at least one detector, the capillary reaction tube comprising at least one portion that is transparent to a signal emitted and/or detected by the detector. 
     
     
         10 . The reaction system as claimed in  claim 1 , further comprising a sampling capillary tube mounted opening into the capillary reaction tube so that at least one reactor can be taken. 
     
     
         11 . The reaction system as claimed in  claim 1 , further comprising at least one diverting capillary tube mounted opening into the capillary reaction tube so that at least one reactor can be diverted to a means for treatment of one or more reactors. 
     
     
         12 . The reaction system as claimed in  claim 1 , further comprising a central control unit connected to the circulating means and configured for:
 controlling the injection of individual drops of reaction mixture into the capillary reaction tube, into the carrier fluid, imposing a velocity and a duration of circulation of the reaction medium, so as to form a plurality of reactors;   controlling the circulation of the carrier fluid by imposing a velocity, duration and direction of circulation of the carrier fluid in the capillary reaction tube;   counting the reactors in the carrier medium and storing the position of each reactor relative to a reference reactor;   recirculating the reservoirs in the capillary reaction tube.   
     
     
         13 . The reaction system as claimed in  claim 5 , in which the central control unit is capable of controlling the injection of drops of separating fluid between two reactors. 
     
     
         14 . The reaction system as claimed in  claim 12 , further comprising at least one reservoir of reagent fluidically connected to the capillary injection tube and/or to the capillary reaction tube so that reagent can be mixed with the reaction mixture, and in which the central control unit is capable of controlling the injection of at least one reagent into the reaction mixture for modifying its composition and/or its chemical and/or physical properties. 
     
     
         15 . The reaction system as claimed in  claim 1 , in which the central control unit is in addition connected to the detector and is capable of storing at least one measurement performed by the detector or detectors. 
     
     
         16 . A method of monitoring a reaction in a reaction mixture, wherein in the method comprises the following steps:
 a) filling a capillary reaction tube with a carrier medium that is immiscible with the reaction mixture;   b) injecting, by means of a capillary injection tube, an individual drop of reaction mixture in the capillary reaction tube, into the immiscible carrier fluid;   c) circulating the carrier fluid so that the drop of reaction mixture is moved relative to the capillary injection tube;   e) repeating steps b) and c) to create an ordered succession of drops of reaction mixture in the carrier fluid to form a plurality of reactors;   f) measuring at least one representative parameter of each reactor;   g) recirculating at least one reactor to measure said at least one representative parameter over time.   
     
     
         17 . The method of monitoring a reaction in a reaction mixture as claimed in  claim 16 , for the culture of microorganisms in a culture medium, comprising the following steps:
 a) filling a capillary culture tube with a carrier medium that is immiscible with the culture medium;   b) injecting, by means of a capillary injection tube, an individual drop of culture medium in the capillary culture tube, into the immiscible carrier fluid;   c) circulating the carrier fluid so that the drop of culture medium is moved relative to the capillary injection tube;   e) repeating steps b) and c) to create an ordered succession of drops of culture medium in the carrier fluid to form a plurality of reactors for culture of microorganisms;   f) measuring at least one representative parameter of each culture reactor, wherein said parameter can be representative of the quantity of microorganisms present in each reactor;   g) recirculating at least one reactor to measure said at least one representative parameter over time.   
     
     
         18 . The method of monitoring a reaction in a reaction mixture as claimed in  claim 16 , further comprising, after step c) and before step e), a step d) comprising injection, into the carrier fluid, of a drop of a separating fluid, immiscible with the carrier fluid and immiscible with the reaction mixture, so that at least one drop of separating fluid is interposed between two reactors and prevents their coalescence. 
     
     
         19 . The method of monitoring a reaction in a reaction mixture as claimed in  claim 16 , in which measurement is carried out by an optical method selected from the group consisting of measurements of absorbance, of diffusion, and of fluorescence, or by an electrical measurement comprising measuring impedance. 
     
     
         20 . The method of monitoring a reaction in a reaction mixture as claimed in  claim 16 , further comprising, after step e), a step f) of recovery of at least one reactor of interest by aspiration of said reactor of interest into a sampling capillary tube mounted opening into the capillary reaction tube.