Beads for use in reactions for the amplification and/or synthesis of a polynucleotide and a device and a method for the production thereof

A method is provided of making meltable beads for use in reactions for the amplification and/or synthesis of a polynucleotide, the method comprising (i) Providing one or more reagents for use in a reaction for the amplification and/or synthesis of a polynucleotide and a substance for promoting the formation of a solid bead; (ii) Providing a reactor device comprising a sample conduit and a first carrier fluid conduit for the flow of immiscible liquids, the sample conduit and first carrier fluid conduit meeting at a junction; (iii) Heating the one or more reagents for use in a reaction for the amplification and/or synthesis of a polynucleotide and the substance for promoting the formation of a solid bead so as to form a liquid comprising the one or more reagents for use in a reaction for the amplification and/or synthesis of a polynucleotide and the substance for promoting the formation of a solid bead in intimate admixture; (iv) Passing the liquid down the sample conduit and a carrier fluid down the first carrier fluid conduit, thus causing the formation of droplets at or downstream of the junction and (v) Causing the formation of solid beads by cooling the droplets. A device for use in such methods is also provided, as is a plurality of beads made by such methods.