Patent ID: 8785120

Claim:
A method for stabilizing at least one species of nucleic acid and species of protein comprised in a sample, said method comprising mixing the sample with a fluid preparation to form a sample preparation comprising the at least one species of nucleic acid and the at least one species of the protein, and wherein the fluid preparation comprises at least one nitrogenous compound which is at least one selected from the group consisting of: a) polyamines; b) amino acids, and oligo and polypeptides; c) nitrogenous heterocyclic compounds including homo or hetero polymers which comprise at least one nitrogenous compound; d) amines of the type R 1 R 2 NR 3 , whereby R 1 , R 2 and R 3 are chosen independently from one another and are selected from the group consisting of H, C 1 -C 5 alkyl groups and aryl groups, whereby R 1 , R 2 and R 3 are not H simultaneously; e) carboxylic acid amides; f) inorganic ammonium salts; g) inner salt compounds containing ammonium groups; h) antibiotics binding nucleic acid; and i) compounds which bind in the small cavity of DNA; wherein an amount of the nitrogenous compound is chosen so as to minimize precipitation of the nucleic acid and protein present during and after said mixing, wherein the ratio of concentration of the at least one species of nucleic acid and protein in the sample preparation is the same as the ratio of concentration of the at least one species of nucleic acid and protein in the sample, and wherein the species of nucleic acid and species of protein in the sample are not encapsulated by a cell membrane.