Field guide for didymo DNA sample collection

This protocol is designed for work in two-person teams for both safety and to maximise sample integrity

Automated microorganism Sample Collection Module

Modified Gelman Sampler obtains representative sample of microorganism population. Proposed Sample Collection Module is based on direct inoculation of selected solid growth media encased in a cartridge at all times except during inoculation. Cartridge can be handled with no danger of contamination to sample or operator

Mars Rover Sample Return: A sample collection and analysis strategy for exobiology

For reasons defined elsewhere it is reasonable to search for biological signatures, both chemical and morphological, of extinct life on Mars. Life on Earth requries the presence of liquid water, therefore, it is important to explore sites on Mars where standing bodies of water may have once existed. Outcrops of layered deposits within the Valles Marineris appear to be ancient lake beds. Because the outcrops are well exposed, relatively shallow core samples would be very informative. The most important biological signature to detect would be organics, microfossils, or larger stromato-like structures, although the presence of cherts, carbonates, clays, and shales would be significant. In spite of the limitations of current robotics and pattern recognition, and the limitations of rover power, computation, Earth communication bandwidth, and time delays, a partial scenario was developed to implement such a scientific investigation. The rover instrumentation and the procedures and decisions and IR spectrometer are described in detail. Preliminary results from a collaborative effort are described, which indicate the rover will be able to autonomously detect stratification, and hence will ease the interpretation burden and lead to greater scientific productivity during the rover's lifetime

A Microfluidic Platform for Precision Small-volume Sample Processing and Its Use to Size Separate Biological Particles with an Acoustic Microdevice.

A major advantage of microfluidic devices is the ability to manipulate small sample volumes, thus reducing reagent waste and preserving precious sample. However, to achieve robust sample manipulation it is necessary to address device integration with the macroscale environment. To realize repeatable, sensitive particle separation with microfluidic devices, this protocol presents a complete automated and integrated microfluidic platform that enables precise processing of 0.15-1.5 ml samples using microfluidic devices. Important aspects of this system include modular device layout and robust fixtures resulting in reliable and flexible world to chip connections, and fully-automated fluid handling which accomplishes closed-loop sample collection, system cleaning and priming steps to ensure repeatable operation. Different microfluidic devices can be used interchangeably with this architecture. Here we incorporate an acoustofluidic device, detail its characterization, performance optimization, and demonstrate its use for size-separation of biological samples. By using real-time feedback during separation experiments, sample collection is optimized to conserve and concentrate sample. Although requiring the integration of multiple pieces of equipment, advantages of this architecture include the ability to process unknown samples with no additional system optimization, ease of device replacement, and precise, robust sample processing

Feasibility of Hair Collection for Cortisol Measurement in Population Research on Adolescent Health

Background: Black–White disparities in adolescent health are widespread and thought to be explained, in part, by exposure to chronic stress. Cortisol assayed from hair is increasingly recognized as a valid and reliable measure for chronic physiological stress, but the feasibility of collecting hair among large probability samples of diverse adolescents is unknown. Purpose: The aim of the study was to investigate participation in hair collection for cortisol analyses in a probability sample of racially and socioeconomically diverse adolescents, including the extent to which sociodemographic factors and adverse exposures were associated with participation. Methods: The study included a probability sample of 516 adolescents conducted in conjunction with a prospective cohort study on adolescent health. Data were collected over 1 week via in-home interviews, ecological momentary assessment, global positioning system methods, and in-home hair collection at the end of the week. Results: Of the 516 eligible youth, 471 (91.3%) participated in the hair collection. Of the 45 youth who did not provide hair samples, 18 had insufficient hair, 25 refused, and 2 did not participate for unknown reasons. Multivariable logistic regression results indicated that non-Hispanic Black youth were less likely than their non-Hispanic White peers to participate due to insufficient hair or refusal (OR = 0.24, 95% CI [0 .09, 0.60]). Despite lower rates of participation, the proportion of Black youth in the participating sample was representative of the study area. No significant differences in participation were found by other sociodemographic characteristics or adverse exposures. Conclusions: Hair collection for cortisol measurement is feasible among a probability sample of racially and socioeconomically diverse adolescents. Hair cortisol analyses may accelerate research progress to understand the biological and psychosocial bases of health disparities

Optimizing Collection of Trace Biological Samples from Vehicle Headrests

Tape-lifting and swabbing are two methods commonly used for collecting biological samples in the United Kingdom and United States to investigate vehicle crimes. Determining the optimal collection method may lead to an increase in generating DNA profiles and crime-solving. The objective of this study is to evaluate the efficiency of adhesive tape and the double-swab collection methods for investigating vehicle crimes with possible touch DNA samples. Two experiments were conducted to evaluate the use of tape-lifts and swabs on spiked common vehicle fabric materials. The efficiency of recovery between the two collection methods was performed using qPCR. The results from the collection of fabric materials indicated tape-lifts outperformed swabbing on cloth and vinyl substrates, while swabbing resulted in comparable recovery on leather substrates. By optimizing sample collection techniques, we aim to aid not only investigations involving vehicles but also other crimes with touch DNA evidence present

Direct in-vial collection for liquid-scintillation assay of carbon-14 and tritium

Dissolution of biological materials combines the simplicity of oxygen-flask combustion with the reproducibility and purity of the final product, and convenience of direct in-vial collection of the sample by the sealed-tube method. It assures quantitative and reproducible recoveries

Investigating TNT loss between sample collection and analysis

Explosives residues are often collected from explosion scenes, and from surfaces suspected of being in contact with explosives, by swabbing with solvent-wetted cotton swabs. It is vital that any explosives traces present on the swabs are successfully extracted and detected when received in a laboratory. However, a 2007 proficiency test initiated by the European Network of Forensic Science Institutes (ENFSI) Expert Working Group on Explosives involving TNT-spiked cotton swabs highlighted that explosives may not always be detected from such samples. This paper outlines work performed to determine potential reasons for this finding. Cotton swabs were spiked using a solution of TNT and stored in nylon bags and glass vials for periods of 1, 2 and 4weeks. Simulated swab extracts were also prepared and investigated. The samples were stored in a freezer, or at room temperature either in the dark or exposed to daylight. Overall, the cotton swabs stored at room temperature and exposed to daylight showed a very rapid loss of TNT over time, whereas cotton swabs stored in the freezer, and all simulated swab extracts, gave high recoveries over time. These results will be of benefit for practicing forensic explosives laboratories and for persons undertaking cold-case reviews involving explosive-based samples.</p