Abstract: The invention provides dry compositions for preparing and loading a sample on a gel for electrophoretic separation. The dry compositions preferably include a tracking dye and a sedimenting agent selected from a five-carbon polyol (e.g., ribitol, arabitol, or xylitol),iso-erythritol, maltitol, and saccharine. Methods for making and using, as well as kits comprising the disclosed compositions, are also provided.

Abstract: The invention provides methods and compositions, e.g., kits, for removing contaminants from nucleic acids in a sample, e.g., environmental or biological samples such as soil, food, plant, animal, microorganism or water samples. The invention provides methods and compositions for isolating nucleic acids from environmental and biological samples in a scaleable process free of contaminating substances that inhibit PCR and other downstream applications. Exemplary sample types include soil, water, plant and food. The methods and compositions of the invention can be used for isolating and/or detecting nucleic acids from prokaryotic and eukaryotic organisms and for detecting multiple types of organisms in a sample. Thus, the methods and compositions of the invention are useful for detecting organisms pertaining to agriculture, forensics biology and/or combating bioterrorism.

Abstract: The invention provides methods for removing a contaminant or inhibitor from a nucleic acid-comprising sample, wherein the contaminant or inhibitor inhibits the amplification or hybridization of the nucleic acid in the sample, or inhibits an enzymatic reaction utilizing the nucleic acid in the sample, the method comprising the steps of: (a) providing a reaction mixture comprising the sample, a chaotropic agent, ammonium acetate or an equivalent, and a detergent, (b) isolating the nucleic acid and remaining contaminants and inhibitors from the reaction mixture in a supernatant; and (c) contacting the nucleic acid supernantant with a flocculant resulting in the further removal of the contaminant or the inhibitor from the supernatant. The invention also provides kits that comprise the components necessary to carry out the method.