Chemical Changes in the Broccoli Volatilome Depending on the Tissue Treatment

The storage of plant samples as well as sample preparation for extraction have a significant impact on the profile of metabolites, however, these factors are often overlooked during experiments on vegetables or fruit. It was hypothesized that parameters such as sample storage (freezing) and sample pre-treatment methods, including the comminution technique or applied enzyme inhibition methods, could significantly influence the extracted volatile metabolome. Significant changes were observed in the volatile profile of broccoli florets frozen in liquid nitrogen at −20 °C. Those differences were mostly related to the concentration of nitriles and aldehydes. Confocal microscopy indicated some tissue deterioration in the case of slow freezing (−20 °C), whereas the structure of tissue, frozen in liquid nitrogen, was practically intact. Myrosinase activity assay proved that the enzyme remains active after freezing. No pH deviation was noted after sample storage - this parameter did not influence the activity of enzymes. Tissue fragmentation and enzyme-inhibition techniques applied prior to the extraction influenced both the qualitative and quantitative composition of the volatile metabolome of broccoli.

Usefulness of Microbiome for Forensic Geolocation: A Review

Forensic microbiomics is a promising tool for crime investigation. Geolocation, which connects an individual to a certain place or location by microbiota, has been fairly well studied in the literature, and several applications have been found. The aim of this review is to highlight the main findings in this field, including the current sample storage, DNA extraction, sequencing and data analysis techniques that are being used, and its potential applications in human trafficking and ancient DNA studies. Second, the challenges and limitations of forensic microbiomics and geolocation are emphasised, providing recommendations for the establishment of this tool in the forensic science community.

Analysis of SARS-CoV-2 RNA Stability and Infectivity in Oropharyngeal Swab Samples

The reliable detection of SARS-CoV-2 genomic RNA and infectious virus particles from patient samples requires a good sample quality. This is especially critical when the sample has to be transported to the analysing laboratory which can take several days. To determine optimal transport conditions, we simulated oropharyngeal swab samples using defined virus amounts and stored the samples at 4 °C or at room temperature for up to four days. Moreover, we analysed the influence of dry swabs in comparison to swabs stored in transport medium. Our results show that care should be taken when analysing samples for infectious SARS-CoV-2 particles since infectivity is strongly influenced by sample storage.

Whole blood platelet impedance aggregometry with the ROTEM platelet device: comparison of 2 anticoagulants and storage times for the establishment of canine reference intervals

The ROTEM platelet device, a point-of-care whole blood platelet impedance aggregometer, is an add-on to the rotational thromboelastometry ROTEM delta device. The latter has been validated in dogs. We examined whether canine whole blood is suited for analysis with the ROTEM platelet device using adenosine-5′-diphosphate (ADP) and arachidonic acid (ARA) as agonists for platelet activation, and if there are significant differences between sample storage times and anticoagulants used. Subsequently, we determined canine reference intervals (RIs) for the ROTEM platelet device for ADP and ARA. In a pilot study, we examined whole blood from 7 dogs after 15-min and 60-min storage of lithium-heparinized samples and 40-min and 80-min storage of hirudinized samples. Statistical analysis showed no significant differences between ROTEM platelet device results for both ADP and ARA in lithium-heparin and hirudin anticoagulated canine whole blood. Lithium-heparinized blood samples analyzed after 15-min storage had the lowest coefficient of variation. RIs were determined for heparinized whole blood samples from 49 dogs after 15 min of storage.

Standard Sample Storage Conditions Have an Impact on Inferred Microbiome Composition and Antimicrobial Resistance Patterns

Previous research has reported effects of DNA isolation, library preparation, and sequencing technology on metagenomics-based microbiome composition; however, the effect of biospecimen storage conditions has not been thoroughly assessed. We examined the effect of common sample storage conditions on metagenomics-based microbiome composition and found significant and, in part, systematic effects.

Analysis of SARS-CoV-2 RNA Stability and Infectivity in Oropharyngeal Swab Samples

The reliable detection of SARS-CoV-2 genomic RNA and infectious virus particles from patient samples requires a good sample quality. This is especially critical when the sample has to be transported to the analysing laboratory which can take several days. To determine optimal transport conditions, we simulated oropharyngeal swab samples using defined virus amounts and stored the samples at 4 °C or at room temperature for up to four days. Moreover, we analysed the influence of dry swabs in comparison to swabs stored in transport medium. Our results show that care should be taken when analysing samples for infectious SARS-CoV-2 particles since infectivity is strongly influenced by sample storage.

Detection and Stability of SARS-CoV-2 Fragments in Wastewater: Impact of Storage Temperature

SARS-CoV-2 wastewater epidemiology suffers from uncertainties concerning sample storage. We show the effect of the storage of wastewater on the detectable SARS-CoV-2 load. Storage at 4 °C for up to 9 days had no significant effect, while storage at −20 °C led to a significant reduction in gene copy numbers.

Influence of Selective Agents (EMJH-STAFF), Sample Filtration and pH on Leptospira Interrogans Serovar Icterohaemorrhagiae Cultivation and Isolation from Swine Urine

Leptospira spp. cause the zoonotic disease leptospirosis, which occurs in numerous mammalians worldwide. Isolation is still important for serotyping and genotyping of Leptospira, which in turn is essential for epidemiological surveillance of leptospirosis and the development of diagnostic tests and vaccines. However, isolation of Leptospira from clinical specimens is inherently insensitive. This study was conducted to examine the influence of selective agents, sample filtration, sample pH and the use of phosphate buffered saline (PBS) buffer for sample storage to improve the success of cultivation and isolation of Leptospira interrogans serovar Icterohaemorrhagiae from swine urine. EMJH (Ellinghausen McCullough, Johnson and Harris) medium including the selective agents sulfamethoxazole, trimethoprim, amphotericin, fosfomycin and 5-fluorouracil (STAFF) increased the success of Leptospira isolation from spiked swine urine samples. Sample filtration yielded only negative results. Isolation in EMJH-STAFF was successful from swine urine with a density as low as 104 Leptospira/mL, and urine with pH ≤ 7 impaired the cultivation rate. Cultivation and isolation were not improved by the addition of PBS to spiked urine samples prior to storage for 24 h at 4 °C. The results of the study demonstrate that cultivation and isolation of leptospires from swine urine can be improved by enhanced methods.