Patent ID: 11873527
Assignee: THE CHINESE UNIVERSITY OF HONG KONG
Field: Biotechnology (Chemistry)
Classification: CPC C  G | IPC C

Claim 18:
19. A computer product comprising a non-transitory computer readable medium storing a plurality of instructions that, when executed on one or more processors of a computer system, control the computer system to perform a method of measuring an amount of cells of a particular cell lineage in a biological sample obtained from a human, the method comprising:
separating a cell-free mixture from a cellular portion of the biological sample, the cell-free mixture including cell-free DNA from a plurality of cell lineages;
performing an assay by contacting DNA fragments in the cell-free mixture with reagents hybridizing to one or more differentially-methylated regions, each of the one or more differentially-methylated regions specific to the particular cell lineage by being hypomethylated or hypermethylated relative to other cell lineages;
detecting a first number of methylated or unmethylated DNA fragments in the cell-free mixture at the one or more differentially-methylated regions based on signals obtained from the assay;
determining a first methylation level using the first number;
obtaining one or more calibration data points, wherein each of the one or more calibration data points specifies (1) a calibration amount of cells of the particular cell lineage and (2) a calibration methylation level, and wherein the one or more calibration data points are determined from a plurality of calibration samples, and wherein the obtaining of the one or more calibration data points includes:
for each calibration sample of a plurality of calibration samples:
measuring the calibration amount of cells of the particular cell lineage in the calibration sample;
detecting a respective number of methylated or unmethylated DNA fragments in the cell-free mixture at the one or more differentially-methylated regions based on signals obtained from the assay applied to the calibration sample; and
determining a respective calibration methylation level using the respective number;
comparing the first methylation level to a calibration methylation level of at least one of the one or more calibration data points; and
estimating the amount of cells of the particular cell lineage in the biological sample based on the comparing.