A novel immunoprobe-based method to assess organ injury status through a biofluid-based cell-free dna (cfdna) assay

A method of detecting an Alu sequence(s) in cell-free (cfDNA) in a biofluidic sample, the method comprising:

• obtaining the biofluidic sample from a human;
• extracting cfDNA from the biofluidic sample;
• forming a reaction mixture by contacting the cfDNA with a nucleic acid probe comprising a nucleotide sequence complementary to at least 20 contiguous nucleotides of the Alu sequence(s) under conditions to allow the probe to hybridize to the cfDNA, wherein the 3′ or 5′ end of the probe is covalently linked to a detectable label, and wherein the cfDNA is not amplified prior to contact with the nucleic acid probe;
• and
• quantifying the amount of cfDNA hybridized to the probe,
• thereby detecting Alu copy number in cfDNA in the biofluidic sample.