DNA diagnostics based on mass spectrometry
AssigneeSequenom, Inc.
InventorsHubert Koster, G. Scott Higgens, Daniel P. Little
Life of this patent
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Abstract
The invention provides fast and highly accurate mass spectrometer based processes for detecting a particular nucleic acid sequence in a biological sample. Depending on the sequence to be detected, the processes can be used, for example, to diagnose a genetic disease or chromosomal abnormality; a predisposition to a disease or condition, infection by a pathogenic organism, or for determining identity or heredity.
Claims46
A process for identifying a target nucleic acid sequence present in a biological sample as being normal or mutant, comprising the steps of:
- a) obtaining the target nucleic acid sequence from a biological sample;
- b) hybridizing the target nucleic acid sequence with
- a mutant primer (M) having sufficient 3' terminal base complementarity to hybridize to a mutation containing portion of the target nucleic acid sequence, or
- a normal primer (N), which is distinguishable from M, having sufficient 3' terminal base complementarity to hybridize to a wildtype sequence in the same portion of the target nucleic acid as M;
- c) contacting the product of step b) with a polymerase enzyme and a nucleoside triphosphate, whereby
- extension from N occurs, if N has hybridized to the target nucleic acid sequence and the nucleoside triphosphate is complementary to the next base in the template target nucleic acid sequence, or
- extension from M occurs, if M has hybridized to the target acid sequence and the nucleoside triphosphate is complementary to the next base in the template target nucleic acid sequence;
- d) ionizing and volatizing the product of step c);
- and
- e) detecting the product of step d) by mass spectrometry, wherein the molecular weight of the product indicates whether the target nucleic acid sequence is normal or mutant.
A process for determining at least one base in a target nucleic acid sequence present in a biological sample, comprising the steps of:
- a) obtaining the target nucleic acid sequence from a biological sample;
- b) performing at least one hybridization of the target nucleic acid sequence with a set of ligation educts for each DNA strand and a DNA ligase, thereby forming a ligation product;
- c) ionizing and volatizing the product of step b);
- and
- d) detecting the ligation product by mass spectrometry and comparing the value obtained with a known value to determine at least one base in the target nucleic acid sequence.
Dependencies are inferred from the claim text.