Method for conducting reactions involving biological molecules in plugs in a microfluidic system

A method for conducting a reaction in plugs in a microfluidic system, comprising the steps of:

• providing the microfluidic system comprising at least two channels having at least one junction;
• continuously flowing an aqueous fluid containing at least one biological molecule and at least one reagent for conducting the reaction between the biological molecule and the at least one reagent through a first channel of the at least two channels;
• continuously flowing a carrier fluid immiscible with the aqueous fluid through the second channel of the at least two channels;
• forming at least one plug of the aqueous fluid containing the at least one biological molecule and the at least one reagent by partitioning the aqueous fluid with the flowing immiscible carrier fluid at the junction of the at least two channels, the plug being substantially surrounded by the immiscible carrier fluid flowing through the channel, wherein the at least one plug comprises at least one biological molecule and the at least one reagent for conducting the reaction with the at least one biological molecule;
• and
• providing conditions suitable for the reaction in the at least one plug involving the at least one biological molecule and the at least one reagent to form a reaction product.