Discrimination of monozygotic twins using mtDNA heteroplasmy through probe capture enrichment and massively parallel sequencing.

Differentiating between monozygotic (MZ) twins remains difficult because they have the same genetic makeup. Applying the traditional STR genotyping approach cannot differentiate one from the other. Heteroplasmy refers to the presence of two or more different mtDNA copies within a single cell and this phenomenon is common in humans. The levels of heteroplasmy cannot change dramatically during transmission in the female germ line but increase or decrease during germ-line transmission and in somatic tissues during life. As massively parallel sequencing (MPS) technology has advanced, it has shown the extraordinary quantity of mtDNA heteroplasmy in humans. In this study, a probe hybridization technique was used to obtain mtDNA and then MPS was performed with an average sequencing depth of above 4000. The results showed us that all ten pairs of MZ twins were clearly differentiated with the minor heteroplasmy threshold at 1.0%, 0.5%, and 0.1%, respectively. Finally, we used a probe that targeted mtDNA to boost sequencing depth without interfering with nuclear DNA and this technique can be used in forensic genetics to differentiate the MZ twins.

In situ vertical alignment of 2D MoS2 layers on GO film: enhanced electrochemical properties for PD-L1 sensing.

There is an urgent need for a flexible and simple programmed cell death ligand 1 (PD-L1) dynamic measurement method enabling real-time monitoring of cancer progression and assessment of immunotherapy efficacy. In the current study, we show facile in situ synthesis of vertical alignment two-dimensional molybdenum disulfide (2D MoS2) layers on graphene-oxide-modified ITO (MoS2┴GO-ITO) using a hydrothermal approach and demonstrate the importance of the alignment of 2D in achieving high-probe capturing, enhanced electrochemical properties and target selectivity during sensing. After modification of designed PD-L1 binding peptides on the MoS2┴GO-ITO, a sensitive PD-L1 electrochemical sensor was designed using vertical alignment MoS2 to capture more probes for PD-L1 recognition and excellent in plane electron transport to accelerate electrochemical signals. The fabricated electrochemical sensor could sensitively determine PD-L1 in a wide linear range of 25-500 ng/mL and exhibit desirable accuracy and reliability in clinical samples application. This simple and sensitive method is likely to investigate further research into the exploration of the perpendicular alignment of 2D surfaces for diverse applications.