Abstract: Use of helper probes in dipstick assays is described. In a dipstick assay to test for the presence of a target nucleic acid in a sample solution, the sample solution is contacted with the contact end of the dipstick to cause the sample solution to move by capillary action to a capture zone of the dipstick at which target nucleic acid is captured. The target nucleic acid may be captured at the capture zone by a capture probe capable of hybridising to the target nucleic acid. A labelled detection probe capable of hybridising to the target nucleic acid may be used to detect the target nucleic acid at the capture zone. A helper probe may be used to enhance the binding of the capture and/or detection probe to the target nucleic acid, thereby improving the sensitivity of target nucleic acid detection. Dipsticks and kits are also described.

Abstract: A method of immersing a flexible web of material in a fluid, the method comprising delivering the web to the fluid and subsequently withdrawing the web from the fluid, wherein the web passes through the fluid not under tension. Thus, the web is not constrained by any tensioning means to follow a particular path through the fluid. The web may instead by constrained by one or more walls confining the fluid, typically walls of a fluid container. In this case the path taken by the web through the fluid and the speed of delivery to and withdrawal from the fluid. The invention also covers corresponding apparatus.

Abstract: In a sampler for sampling a first portion of a liquid flow, the liquid flow enters at a sampler inlet (12). The sample passes through a valve (30) into a sample chamber (8) and then the valve closes, diverting the remainder of the liquid flow to a sampler overflow (6). The valve comprises a valve inlet (24) coupled to the sampler inlet, a valve outlet (38, 36) opening into the sample chamber and positioned, in use, substantially below the valve inlet, a shut-off chamber (32) separating the valve outlet from the valve inlet, and a valve overflow (34) leading from the shut-off chamber to the sampler overflow (6). When the liquid level in the sample chamber rises to a predetermined level it disrupts the flow of liquid through the valve outlet and diverts later flow through the valve inlet into the shut-off chamber and through the valve overflow.

Abstract: Use of helper probes in dipstick assays is described. In a dipstick assay to test for the presence of a target nucleic acid in a sample solution, the sample solution is connected with the contact end of the dipstick to cause the sample solution is contacted with the contact end of the dipstick to cause the sample solution to move by capillary action to a capture zone of the dipstick at which target nucleic acid is captured. The target nucleic acid may be captured at the capture zone by a capture probe capable of hybridising to the target nucleic acid. A labelled detection probe capable of hybridising to the target nucleic acid may be used to detect the target nucleic acid at the capture zone. A helper probe may be used to enhance the binding of the capture and/or detection probe to the target nucleic acid, thereby improving the sensitivity of target nucleic acid detection. Dipsticks and kits are also described.