Abstract: The present invention provides a method for depleting host nucleic acid in a biological sample, said sample having been previously obtained from an animal host and having been subjected to treatment to lyse host cells present in the sample, and having been subjected to a treatment to deplete nucleic acid released from host cells within said sample or otherwise to render such nucleic acid unidentifiable, the method comprising: (a) depleting host mitochondria or host mitochondrial DNA (mtDNA) present in the treated sample; and (b) extracting and/or analysing remaining nucleic acid from the treated sample. Also provided is a related kit comprising reagents for performing the method. Further claimed is a method for isolating mitochondrial DNA after host cells have been lysed and host cell nucleic acids have been removed from the sample.

Abstract: Aqueous compositions are for storing a biological sample for subsequent nucleic acid testing. The compositions include a first component, which includes an anionic detergent in an amount from about 1% to 20% (w/v), a Group I metal hydroxide in an amount from about 1% to 5% (w/v), a chelating agent in an amount from about 0.5% to 5% (w/v), and a first buffer. The composition further includes a diluting component selected from water, a second buffer, a Transport Medium, Sodium Chloride (aq), and combinations. The first component can be diluted up to a maximum of about 50% (v/v) with the diluting component.

Abstract: The present invention provides a method for depleting host nucleic acid in a biological sample, said sample having been previously obtained from an animal host and having been subjected to treatment to lyse host cells present in the sample, and having been subjected to a treatment to deplete nucleic acid released from host cells within said sample or otherwise to render such nucleic acid unidentifiable, the method comprising: (a) depleting host mitochondria or host mitochondrial DNA (mtDNA) present in the treated sample; and (b) extracting and/or analysing remaining nucleic acid from the treated sample. Also provided is a related kit comprising reagents for performing the method. Further claimed is a method for isolating mitochondrial DNA after host cells have been lysed and host cell nucleic acids have been removed from the sample.