b'Several cancers are characterized by germline point mutationsbe used to distinguish base differences by PCR amplification, in specific genes, such as the BRCA1 mutation in breast cancerT/C genotyping using SNaPshot single-base extension (SBE) and BRCA2 mutation in ovarian cancer. However, even formultiplex assay, followed by fragment analysis.such well-characterized cancers, mutations involving genomicCell line authentication and human sample matchingrearrangements have been found in a subset of cases [9]. TheCancer cell lines are heavily relied upon for biomedical research, MLPA assay can be used to interrogate these genomic loci inincluding cancer-related studies. To ensure reproducibility of cases where the initial screen is negative, even though there is ascientific research, cell line authentication (CLA) is of paramount high probability of disease inheritance. For instance, the MLPAimportance to confirm the cells origin, as well as to check for assay has been used to show deletions and duplications in thecontamination and genomic instability. CLA is performed by BRCA1 gene in patients with a history of breast cancer but whogenerating a profile of highly variable short tandem repeat (STR) were negative for BRCA point mutations [10]. markers from microsatellite loci with varying number of repeats MLPA technology can also be used to detect epigeneticfor a particular cell line/type, and then comparing it with the modifications involving DNA methylation [11] that contribute toallelic profiles present at these loci against known standards. A cancer formation. The methylation-specific MLPA (MS-MLPA)study aimed at authenticating 278 human tumor cell lines used in assay has probes that bind and ligate over a GCGC sequence,China found that nearly 46% of the samples were either cross-which is also a cleavage site for a methylation-sensitive restrictioncontaminated or misidentified [13]. Needless to say, such findings enzyme, HhaI. The enzyme cleaves the probes that are ligatedcan have massive implications on the conclusion of studies that and hybridized to unmethylated DNA, while the probes bound toutilize such cell lines. The Applied Biosystems CLA GlobalFiler methylated DNA remain intact and are subsequently amplifiedPCR Amplification Kit generates a molecular fingerprint for 24 by PCR. This assay has been used to determine promoterdifferent STR loci, while the Applied Biosystems CLA IdentiFiler methylation status of tumor suppressor genes p15 and p73 inPlus PCR Amplification Kit analyzes 16 STR loci.acute myeloid leukemia cell lines [11].In addition to CLA, STR typing can be used for human sample Epigenetic modification matching. CAR T cell therapy is a potent cellular immunotherapy Changes in DNA methylation patterns are also characteristicthat has seen great success in the treatment of hematological of oncogenesis. Genome-wide hypomethylation ormalignancies. CAR T cell preparation involves the isolation, hypermethylation, particularly of cytosines 5 to guanosinesactivation, engineering, and expansion of patient-derived T cells. (CpG) within the promoter regions of tumor repressor genes, hasEvery step of this process can affect the efficacy and consistency been shown to be associated with cancer development [12]. Theof a CAR T cell product, and requires thorough characterization SNaPshot multiplex assay can also be used to investigate DNAto ensure that the product meets predesigned specifications. methylation patterns following bisulfite treatment of genomicSTR typing can be used to confirm that the CAR T cells match DNA. Sodium bisulfite converts unmethylated cytosines intothe starting T cell population, ensuring the identity of the final uracil, which are subsequently replaced as thymine in PCR; inCAR T product [14].contrast, methylcytosines remain unchanged. This feature can Contents 17'