Multiplex ligation-dependent probe amplification

Identification of deletions or duplications can indicate pathogenic mutations, thus MLPA is an important diagnostic tool used in clinical pathology laboratories worldwide.

[2] The first applications included the detection of exon deletions in the human genes BRCA1, MSH2 and MLH1, which are linked to hereditary breast and colon cancer.

The process consists of multiple steps:[3] Each probe pair consists of two oligonucleotides, with sequence that recognizes adjacent sites of the target DNA, a PCR priming site, and optionally a "stuffer" to give the PCR product a unique length when compared to other probe pairs in the MLPA assay.

MLPA can successfully and easily determine the relative copy number of all exons within a gene simultaneously with high sensitivity.

The signal strengths of the probes are compared with those obtained from a reference DNA sample known to have two copies of the chromosome.

If an extra copy is present in the test sample, the signals are expected to be 1.5 times the intensities of the respective probes from the reference.

[14] Recent studies have shown that MLPA (as well as another variants such as iMLPA) is a robust technique for inversion characterisation.

They call these new method iMLPA[15] and its procedure is the same as MLPA but there are necessary two additional steps at the beginning: The probe design is quite similar.