Abstract: The present invention relates to the field of improving and stabilizing concentrated solutions and in particular to improving and stabilizing concentrated solutions for the extraction of nucleic acids from sample material. Thus, the present invention, further, relates to the field of molecular biology. The present invention describes the use of betaines for stabilizing organic salts or chaotropic agents in solution which is particularly useful in cases where organic salts or chaotropic agents are present at high concentration such as for example chaotropic agents in buffers for the extraction of nucleic acids from sample material. The present invention describes the corresponding buffers and further relates to processes for the extraction of nucleic acids from sample material as well as processes for the analysis of sample material. Moreover, the present invention relates to kits and cartridges comprising at least one container with the corresponding buffer.

Abstract: The invention relates to a method and an apparatus for the detection of occupied binding sites (15) in a sample (10), preferably for the detection of a fluorescent labeling element bound to probes on a solid surface. The method comprises the scanning of said sample (10) with a spot (26) of laser light (22) and the detection of target specific responses, e.g. fluorescent light (32), with a detection unit (30). The size of the scanning spot (26) is chosen small enough such that only one occupied binding site (15) is irradiated at the same time. A location (11) is classified as an occupied binding site (15) if a target specific response is observed in repeated scans of said location. Such repeated scans particularly allow to discriminate between specific and nonspecific binding.