How to better select SARS-CoV-2 preservation solution of virus nucleic acid testing.

BACKGROUND: Sampling and testing for SARS-CoV-2 is a widely recognized method for identifying patients with COVID-19. However, there is limited research available on the stability of nucleic acids in viral storage solutions. METHODS: This paper investigates the components that provide better protection for virus and nucleic acid detection. The study utilized real-time quantitative fluorescent PCR to detect SARS-CoV-2 and evaluate the preservation effect and stability of SARS-CoV-2 viral storage solution under various conditions, including different guanidinium salts, brands, and storage conditions. RESULTS: All brands of inactivated virus preservation solutions demonstrated effective preservation and stability. However, 0.5 mol/L guanidine hydrochloride and guanidine isothiocyanate solutions exhibited poor antiseptic effects. Additionally, refrigerated storage showed better preservation compared to room temperature storage. CONCLUSIONS: We recommend using inactivated virus collection solution to preserve and transport samples and testing preferably within 6 hours to reduce false negatives of NAT results.

Dual detection of bioaccumulated Hg2+ based on luminescent bacteria and aggregation-induced emission.

The development of a sensitive and reliable method for the detection of bioaccumulated heavy metal toxins is highly desirable for biotoxicity evaluation. However, the conventional biotoxicity evaluation method based on luminescent bacteria suffers from only being able to detect the overall toxicity without selectivity in light-off detection mode. Although various synthetic fluorescent probes have been developed for the selective detection of heavy metal ions, they usually suffer from aggregation-caused quenching after local accumulation in biological systems. To tackle these challenges, we herein develop a dual detection strategy for bioaccumulated Hg2+ based on turn-off of the bioluminescence of P. phosphoreum bacteria by disrupting the quorum sensing system and turn-on of the photoluminescence of an aggregation-induced emission (AIE) probe by forming aggregates with Hg2+ inside the bacteria. It is expected that the dual detection strategy would find broad applications in the evaluation of bioaccumulated toxins.