3.3 DNA-PAINT
The DNA-PAINT technique utilises the transient binding of fluorescently
labelled DNA oligonucleotides (“imager”) to their complementary target
strands (“docking”) to achieve the blinking effect of SMLM techniques
(Schnitzbauer et al., 2017) and obtain a resolution of 10 nm (Figure
2c). DNA-PAINT has been used to determine the amount and distribution of
αV integrin accumulation regulated by the purinergic
P2Y2 receptor in pancreatic ductal adenocarcinoma (Tomas
Bort et al., 2023). A modification of DNA-PAINT, quantitative PAINT
(qPAINT), allows accurate molecular counting and was used for the
quantitation of the P2Y2 oligomer composition (Joseph et
al., 2021). DNA-PAINT limitations include complex probe design,
efficient delivery of the imager DNA nucleotides to the docking target,
and slow data acquisition rates. However, DNA-PAINT is compatible with
other SRN techniques, such as RESI, allowing the achievement of even
higher resolution, making it a technique of choice for many
applications.