A fitting for coupling fluidic paths, comprising: a coupling body (28, 48 66, 88, 102) having a threaded bore, a first bore and a second bore for receiving a tube assembly, the first bore extending from an end of the threaded bore and the second bore extending from an end surface of the first bore, the second bore having a diameter that is less than a diameter of the first bore and having a sealing surface (46, 64, 86, 108) at an end opposite to the first bore with a channel extending from the sealing surface (46, 64, 86, 108) to pass a fluid; a compression screw having an axial bore, a threaded portion in engagement with the threaded bore of the coupling body (28, 48, 66, 88, 102) and a drive surface; a tube assembly having a sleeve and a tube (42, 104) disposed through the sleeve, the tube (42, 104) having an endface and being secured to the sleeve proximate to the endface, wherein a portion of the tube (42, 104) that includes the endface protrudes from the sleeve, the tube assembly extending through the axial bore of the compression screw; a collet (68, 84, 114) secured to an outer surface of the sleeve and having a first end configured to receive the drive surface of the compression screw and a second end; and characterised in that: a polymer seal (82, 110) having a lower seal portion and an upper seal portion (92, 96), the lower seal portion having a channel to pass a fluid and a diameter substantially the same as the diameter of the second bore, the upper seal portion (92, 96) having an opening to receive an end of the tube assembly and having a diameter substantially the same as the diameter of the first bore, wherein a fluidic seal is formed between the endface of the tube (42, 104) and the sealing surface (46, 64, 86, 108) of the second bore by the polymer seal (82, 110) when the second end of the collet (68, 84, 114) is in contact with the upper seal portion (92, 96) of the polymer seal (82, 110). a coupling body (28, 48 66, 88, 102) having a threaded bore, a first bore and a second bore for receiving a tube assembly, the first bore extending from an end of the threaded bore and the second bore extending from an end surface of the first bore, the second bore having a diameter that is less than a diameter of the first bore and having a sealing surface (46, 64, 86, 108) at an end opposite to the first bore with a channel extending from the sealing surface (46, 64, 86, 108) to pass a fluid; a compression screw having an axial bore, a threaded portion in engagement with the threaded bore of the coupling body (28, 48, 66, 88, 102) and a drive surface; a tube assembly having a sleeve and a tube (42, 104) disposed through the sleeve, the tube (42, 104) having an endface and being secured to the sleeve proximate to the endface, wherein a portion of the tube (42, 104) that includes the endface protrudes from the sleeve, the tube assembly extending through the axial bore of the compression screw; a collet (68, 84, 114) secured to an outer surface of the sleeve and having a first end configured to receive the drive surface of the compression screw and a second end; and characterised in that: a polymer seal (82, 110) having a lower seal portion and an upper seal portion (92, 96), the lower seal portion having a channel to pass a fluid and a diameter substantially the same as the diameter of the second bore, the upper seal portion (92, 96) having an opening to receive an end of the tube assembly and having a diameter substantially the same as the diameter of the first bore, wherein a fluidic seal is formed between the endface of the tube (42, 104) and the sealing surface (46, 64, 86, 108) of the second bore by the polymer seal (82, 110) when the second end of the collet (68, 84, 114) is in contact with the upper seal portion (92, 96) of the polymer seal (82, 110). a polymer seal (82, 110) having a lower seal portion and an upper seal portion (92, 96), the lower seal portion having a channel to pass a fluid and a diameter substantially the same as the diameter of the second bore, the upper seal portion (92, 96) having an opening to receive an end of the tube assembly and having a diameter substantially the same as the diameter of the first bore, wherein a fluidic seal is formed between the endface of the tube (42, 104) and the sealing surface (46, 64, 86, 108) of the second bore by the polymer seal (82, 110) when the second end of the collet (68, 84, 114) is in contact with the upper seal portion (92, 96) of the polymer seal (82, 110).