Methods for clinical diagnosis
AssigneeSimeg Ltd.
InventorMaj Anita Hulten
Life of this patent
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Abstract
A method for the identification of foetal cell nuclei, chromosomes or DNA in a maternal blood or vaginal sample, said method comprising: a) subjecting chromosomes of cell nuclei in said sample to exonucleolytic digestion by an enzyme so as to remove end regions of each chromosome; and b) detecting the presence of a DNA sequence remaining in foetal DNA but absent from maternal DNA as a result of said digestion process. Once identified, the foetal DNA can be subject to diagnosis for example to detect chromosomal abnormalities.
Claims30
A method for the identification of foetal cell nuclei, containing chromosomes and DNA, in a maternal blood or vaginal sample, said method comprising (a) subjecting chromosomes of cell nuclei in said sample to exonucleolytic digestion by an enzyme so as to remove end regions of each chromosome, and (b) detecting the presence of DNA sequences remaining in foetal chromosomes but absent from maternal DNA as a result of said digestion process.
A method according to any one of the preceeding claims wherein the said DNA sequences remaining in foetal chromosomes are telomere sequences.
A method according to any one of the preceeding claims wherein the said DNA sequence is detected using a primary labelled probe which is specific for said sequences.
A method according to any one of the preceeding claims wherein foetal cell nuclei identified are separated from maternal cell nuclei by a flow sort method.
A method according to any one of the preceeding claims wherein the enzyme is BAL31.
A method according to any one of claims 1 to 12 wherein exonucleolytic digestion is effected in stages in which, in a first step, 3′ extension DNA is removed, in a second step, 3′-5′ ss regions are excised and in a third step, ss regions are digested.
A method according to any one of the preceeding claims wherein foetal cell nuclei containing chromosomes and DNA identified are subjected to prenatal diagnosis.
A kit for identifying foetal cell nuclei, containing chromosomes and DNA in a maternal blood or vaginal sample, said kit comprising an exonucleolytic enzyme capable of digesting terminal segments of chromosomes, and a labelled probe for detecting specific DNA sequences found in a terminal segments of chromosomes.
A method for the identification of foetal cell nuclei, containing chromosomes and DNA in a maternal blood or vaginal sample, substantially as herein before described with reference to the Examples.
A kit for the identification of foetal cells nuclei, containing chromosomes and DNA in a maternal blood or vaginal sample, substantially as herein before described.
Dependencies are inferred from the claim text.