FISH (Fluorescent in situ hybridisation) and PCR (polymerase chain reaction) like RT-PCR and QF PCR tests can detect specific aneuploidy. Whereas, microarray-based CGH (comparative genomic hybridization) test can be used as high-resolution whole-genome scan for the detection or screening of unknown (non-specific) abnormalities, mutation or genomic imbalance including deletions, duplication and aneuploidies. Microarray-based CGH cannot detect balanced translocations or inversions. So FISH and PCR can detect specific (known) chromosomal abnormalities whereas microarray-based CGH is better suited for screening unknown (non-specific) chromosomal abnormalities.