The test uses a blood sample, from which genetic material is extracted. Specific probe pairs, one for each exon or region of interest, hybridize to their target sequence and are then ligated together only if both halves bind correctly. The ligated probes are amplified together in a single reaction and separated by size, and the amount of signal from each probe reflects how many copies of that region are present compared to a normal reference sample. Turnaround time is typically one to two weeks, and results are reported as normal copy number, deletion, duplication, or occasionally an inconclusive finding requiring repeat or confirmatory testing.