A novel loop-mediated isothermal amplification method for identification of four body fluids with smartphone detection.

Messenger RNA profiling for body fluid identification (bfID) is a useful approach to collect contextual information associated with a crime. Current methods require costly fluorescent probes, lengthy amplification protocols and/or time-consuming sample preparation. To simplify this process, we developed a bfID method that has the potential to be rapid in analysis time, inexpensive and fluorescence-free, combining a universal operating procedure with a high-throughout (microwell plate) platform for simultaneous detection of mRNA markers from whole blood, semen, saliva, and vaginal fluid.

Acoustic trapping of sperm cells from mock sexual assault samples.

We report the successful separation of sperm cells from a relevant composition of mock sexual assault samples using a novel acoustic differential extraction (ADE) technology. A multi-layer microfluidic device fabricated in a non-photolithographic process from glass and polydimethylsiloxane (PDMS) was capable of interfacing with custom-built instrumentation to exploit a standing acoustic wave for the trapping of individual sperm cells in a sample containing an abundance of epithelial cells. Samples were generated from buccal and vaginal swabs to mimic post-coital vaginal swabs, and processed through the ADE system followed by DNA extraction of the captured cells with amplification of DNA using a custom short tandem repeat (STR) chemistry.

Rapid multiplex DNA amplification on an inexpensive microdevice for human identification via short tandem repeat analysis.

Forensic DNA analysis requires several steps, including DNA extraction, PCR amplification, and separation of PCR fragments. Intuitively, there are numerous situations where it would be beneficial to speed up the overall DNA analysis process; in this work, we focus on the most time-consuming component in the analysis pipeline, namely the polymerase chain reaction (PCR). Primers were specially designed to target 10 human genomic loci, all yielding amplicons shorter than 350 bases, for ease of downstream integration with on-board microchip electrophoresis.

A centrifugal microfluidic device with integrated gold leaf electrodes for the electrophoretic separation of DNA.

Current conventional methods utilized for forensic DNA analysis are time consuming and labor-intensive requiring large and expensive equipment and instrumentation. While more portable Rapid DNA systems have been developed, introducing them to a working laboratory still necessitates a high cost of initiation followed by the recurrent cost of the devices. This has highlighted the need for an inexpensive, rapid and portable DNA analysis tool for human identification in a forensic setting.

Microfluidic enzymatic DNA extraction on a hybrid polyester-toner-PMMA device.

To date, the forensic community regards solid phase extraction (SPE) as the most effective methodology for the purification of DNA for use in short tandem repeat (STR) polymerase chain reaction (PCR) amplification. While a dominant methodology, SPE protocols generally necessitate the use of PCR inhibitors (guanidine, IPA) and, in addition, can demand timescales of up to 30 min due to the necessary load, wash and elution steps. The recent discovery and characterization of the EA1 protease has allowed the user to enzymatically extract (not purify) DNA, dramatically simplifying the task of producing a PCR-ready template.

An integrated sample-in-answer-out microfluidic chip for rapid human identification by STR analysis.

A fully integrated microfluidic chip for human identification by short tandem repeat (STR) analysis that includes a unique enzymatic liquid preparation of the DNA, microliter non-contact PCR, and a polymer that allows a high-resolution separation within a compact microchip footprint has been developed. A heat-activated enzyme that digests biological materials is employed to generate the target yield of DNA from a buccal swab or FTA paper. The microfluidic architecture meters an aliquot of the liberated DNA and mixes it with the PCR reagents prior to non-contact IR-mediated PCR amplification.

Metformin induced expression of Hsp60 in human THP-1 monocyte cells.

Metformin is in widespread clinical use for the treatment of diabetes mellitus in patients. It has been shown to inhibit mitochondrial bioenergetic functions by inhibiting complex I of the electron transport chain. The expression of mitochondrial-specific molecular stress protein Hsp60 is a key consequence of mitochondrial impairment.

Prevalence and numbers of coliphages and Campylobacter jejuni bacteriophages in New Zealand foods.

Vegetable samples were tested for the presence of coliphages. None of the 55 samples contained these phages at concentrations greater than 10 g(-1) (the limit of detection). Spiking and recovery experiments indicated that the method was efficient at detecting coliphage T4 added to the food, and so it was concluded that phage titres were not being falsely underestimated.