Amplification-free detection of genetically modified crops via spatial confinement CHA/HCR-aided surface-enhanced resonance Raman spectroscopy.

To distinguish genetically modified (GM) crops, we developed a target RNA amplification-free surface-enhanced resonance Raman scattering (SERRS) biosensor for the CaMV35S promoter RNA in GM crops by integrating enzyme-free, spatial confinement catalytic hairpin assembly (CHA) and hybridization chain reaction (HCR). A magnetic-plasmonic composite probe modified with the first sequence of CHA was first fabricated. A small amount of target RNA can activate it to initiate the CHA, and the CHA efficacy benefits from the spatial confinement effect provided by the composite probe.

A CRISPR/Cas12a-SERS platform for amplification-free detection of African swine fever virus genes.

A surface-enhanced Raman scattering (SERS) strategy combined with a CRISPR/Cas12a system is designed for the amplification-free gene detection of African swine fever virus (ASFV). A SERS sensing probe was fabricated by conjugating plasmonic SERS tags on the magnetic bead (MB) surface with an single-stranded DNA (ssDNA) as a linker. The target ASFV gene-activated Cas12a protein starts the trans-cleavage function on the linker ssDNA, which causes the release of SERS tags, leading to a decrease of the SERS signal detected above the collective MBs.

[Nine polymorphisms of fibrinogen gene and their association with plasma fibrinogen levels in Hainan Han population].

Objective: To investigate the allelic frequencies of polymorphisms of alpha Taq I and beta Bcl I, Hinf I A/C, 448 G/A, beta BsmA I G/C, +1689T/G, -148C/T, -249C/T, -455G/A in Hainan Han population and their association with plasma fibrinogen level.

Methods: Turbidmetric assay was used to measure plasma fibrinogen level of two hundred and thirty-eight healthy individuals. The genotypes were characterized by PCR-RFLP and sequence analysis.