Abstract: The present invention concerns a polypeptide comprising the N-terminal fragment of a cystatin, and/or a cystatin expression inducer for use for the treatment of sterility and/or infertility, and a method of diagnosing and/or predicting sterility and/or infertility of a subject and/or of a couple of subjects, which method comprises measuring the level of at least one cystatin in a biological sample of a male subject and/or measuring the level of at least one cystatin in a biological sample of a female subject, and optionally measuring further the level of at least one cathepsin in a biological sample of said male of female subject.

Abstract: The present invention concerns a method for comparing, in at least two samples A1 and A2, the amount of RNA of a target gene t, wherein a fixed amount of external control sample C is added during RNA extraction of samples A1 and A2 and a fixed amount of external control D RNA is added to the extracted RNA from A1+C and A2+C before reverse transcription.

Abstract: In one aspect, the present invention concerns methods and kits for quantifying a target nucleic acid in a sample. In embodiments, a method comprises sequestrating the target nucleic acid by one or more interactors to form a sequestered conjugate that will be further labeled to form a labeled conjugate. The signal produced by the labeled conjugate is measured and correlated to the amount of the target nucleic acid. In another aspect, the present invention concerns a method for quantifying a target nucleic acid in a sample by a reaction of the nucleic acids in the sample with a nucleic acid interactor or set of interactors to form a conjugate. The conjugate is then sequestered from the rest of the sample with a molecule bound to a support, to form a sequestered conjugate. The sequestered conjugate is labeled to form a labeled conjugate. The signal produced by the labeled conjugate is measured and correlated to the amount of the target nucleic acid.

Abstract: A method for labeling a product includes a step of adding on or in the product a plurality of single-stranded polynucleotides, which plurality of polynucleotides includes at least one target polynucleotide constituted of a single-stranded polynucleotide of predetermined length and sequence, and decoy polynucleotides which have identical or different predetermined lengths and identical or different predetermined sequence, which decoy polynucleotides have a length or lengths identical to or different from and sequences different from the sequence of the at least one target polynucleotide, wherein each of the target and decoy polynucleotides does not hybridize with any of the other polynucleotides of the plurality of polynucleotides and wherein the polynucleotides of the plurality of polynucleotides are deoxyribonucleic or ribonucleic acid sequences, respectively having the same proportion of the four, natural or modified, bases A, C, G, and T, or A, C, G and U.