Abstract: A fluorescence detection apparatus for analyzing samples located in a plurality of wells in a thermal cycler and methods of use are provided. In one embodiment, the apparatus includes a support structure attachable to the thermal cycler and a detection module movably mountable on the support structure. The detection module includes one or more channels, each having an excitation light generator and an emission light detector both disposed within the detection module. When the support structure is attached to the thermal cycler and the detection module is mounted on the support structure, the detection module is movable so as to be positioned in optical communication with different ones of the plurality of wells. The detection module is removable from the support structure to allow easy replacement.

Abstract: Disclosed are methods and compositions for estimating the crossover point of a molecular separation system.

Abstract: A sample cartridge block that includes a first plate, a second plate and a third plate. The third plate is thermally connected to the first plate and the second plate. In some embodiments, the block is capable of holding a relatively high density of sample cartridges. In certain embodiments, the block provides good sample temperature stability while the sample temperature is held constant or while the sample temperature is being changed. According to the invention, a sample block may include one material or more than one material. Preferably, a sample cartridge block has a relatively low thermal mass. In some embodiments, the first plate of a sample cartridge block may have a larger surface area than the surface area of the third plate. According to the present invention, the first plate of the sample cartridge block may be thermally connected to a temperature controller. In certain embodiments, a sample cartridge block may have a relatively large surface area in contact with a temperature controller.