Transport of silica encapsulated DNA microparticles in controlled instantaneous injection open channel experiments

Settling of superparamagnetic silica encapsulated DNA microparticles in river water

“…Briefly, synthetic double‐stranded DNA (dsDNA) was firstly bound with positively charged iron oxide nanoparticles (IONPs), thereafter, these DNA‐tagged IONPs were encapsulated within a silica shell. For DNA analysis, a protocol was followed similar to that described in Tang et al (2021). Briefly, to release DNA, the protective silica shell was dissolved by buffered oxide etch solution (BOE).…”

“…The relatively large error bars across all experiments were due to random variations of qPCR readings, differences per sample in effect of inhibitors, and dilution issues. The first can account for $±20% of mass variations, and has been widely recognized and discussed in previously published research papers on DNA-based tracers (Mikutis et al, 2018;Tang et al, 2021). With regard to the second, in our qPCR lab, we optimized the protocol so that the trade-off was minimized between diluting the inhibitors and consuming too much time for the labour-intensive washing and up-concentration.…”

Effect of concentration of silica encapsulated ds-DNA colloidal microparticles on their transport through saturated porous media

“…The concept of increased colloid-colloid collision leading to removal of weakly deposited colloids has also been mentioned for zinc oxide nanoparticles [78] under alkaline conditions from soil particles or removal of latex colloids [76]. Though inter-colloidal collisions have been reported to cause colloidal aggregation and therefore higher deposition [23], we think SiDNASi aggregation was unlikely to occur under current environmental conditions: for higher SiDNASi concentrations than the ones we used, Tang et al, [80] reported a constant hydrodynamic diameter in 5 mM phosphate buffer in both quiescent (4 h) and mixing (3 h) conditions. Furthermore, if aggregation as a function of increasing SiDNASi concentrations would have occurred, then this would have likely caused more retention; instead we observed less retention with increasing injection concentration.…”

“…pH, temperature and ionizing radiation) environmental stresses, high chemical and thermal stability, nontoxicity, ability to be synthesized and dissolute at room temperature and chemical compatibility with nucleic acid analysis [53,56,60]. Use of these particles is also gaining increasing attention as a potential hydrological tag for investigating subsurface [4,51,54,66], surface [27,28,45,80] and glacial [20] hydrological systems. The concentration range was selected based on its relevance in natural subsurface systems.…”

A Virological Perspective on the Use of Bacteriophages as Hydrological Tracers

“…Consequently, isotope tracers have been preferentially used in small catchment areas [12], and their application to larger scales remains highly challenging [20]. For overcoming this status quo, complementary tools have been proposed, such as distributed fibre-optic temperature sensing [21,22], thermal infrared (IR) imagery [23,24], the use of terrestrial diatoms as environmental biological tracers of hydrological connectivity across multiple scales [25,26], artificial DNA tracers [27,28] or the injection of bacteriophages [14,29]. Bacteriophages are viruses that specifically infect bacterial hosts.…”