Abstract:Body fluids are a category of biological evidence that provides critical contextual clues for forensic investigations; blood, saliva, and semen are three of the most prevalently tested fluids in a forensic laboratory. Some of the existing colorimetric presumptive forensic assays for these fluids include: the phenolphthalein test or luminol test for blood, the acid phosphatase (AP) test or prostate-specific antigen (PSA) lateral flow assay for seminal fluid, and the alpha-amylase test for saliva. Even though th… Show more
“…Notably, the method does not destroy the DNA evidence, which can also be used for profiling. The study constitutes the first step towards an innovative approach to identifying body fluids for forensic purposes [74].…”
Section: Application Of Lamp In Forensicsmentioning
In 1998, when the PCR technique was already popular, a Japanese company called Eiken Chemical Co., Ltd. designed a method known as the loop-mediated isothermal amplification of DNA (LAMP). The method can produce up to 109 copies of the amplified DNA within less than an hour. It is also highly specific due to the use of two to three pairs of primers (internal, external, and loop), which recognise up to eight specific locations on the DNA or RNA targets. Furthermore, the Bst DNA polymerase most used in LAMP shows a high strand displacement activity, which eliminates the DNA denaturation stage. One of the most significant advantages of LAMP is that it can be conducted at a stable temperature, for instance, in a dry block heater or an incubator. The products of LAMP can be detected much faster than in standard techniques, sometimes only requiring analysis with the naked eye. The following overview highlights the usefulness of LAMP and its effectiveness in various fields; it also considers the superiority of LAMP over PCR and presents RT-LAMP as a rapid diagnostic tool for SARS-CoV-2.
“…Notably, the method does not destroy the DNA evidence, which can also be used for profiling. The study constitutes the first step towards an innovative approach to identifying body fluids for forensic purposes [74].…”
Section: Application Of Lamp In Forensicsmentioning
In 1998, when the PCR technique was already popular, a Japanese company called Eiken Chemical Co., Ltd. designed a method known as the loop-mediated isothermal amplification of DNA (LAMP). The method can produce up to 109 copies of the amplified DNA within less than an hour. It is also highly specific due to the use of two to three pairs of primers (internal, external, and loop), which recognise up to eight specific locations on the DNA or RNA targets. Furthermore, the Bst DNA polymerase most used in LAMP shows a high strand displacement activity, which eliminates the DNA denaturation stage. One of the most significant advantages of LAMP is that it can be conducted at a stable temperature, for instance, in a dry block heater or an incubator. The products of LAMP can be detected much faster than in standard techniques, sometimes only requiring analysis with the naked eye. The following overview highlights the usefulness of LAMP and its effectiveness in various fields; it also considers the superiority of LAMP over PCR and presents RT-LAMP as a rapid diagnostic tool for SARS-CoV-2.
“…In addition to end point analysis, the absorbance of these two peaks could be measured in real time and applied to determine amplification results, similarly to what was shown for the pH-based colorimetric method used in the high-throughput Color Health COVID-19 colorimetric LAMP assay 27 . For simple applications using smartphone cameras or basic image analysis, the processes and tools developed for colorimetric LAMP such as the LAMP Plate Reader app ( https://apps.apple.com/us/app/lamp-plate-reader/id1529271060 ) and hue/saturation analysis 40 , 41 can be used for any of the colorimetric dyes and are suitable for PAPS. Fig.…”
Detection of nucleic acid amplification has typically required sophisticated laboratory instrumentation, but as the amplification techniques have moved away from the lab, complementary detection techniques have been implemented to facilitate point-of-care, field, and even at-home applications. Simple visual detection approaches have been widely used for isothermal amplification methods, but have generally displayed weak color changes or been highly sensitive to sample and atmospheric effects. Here we describe the use of pyridylazophenol dyes and binding to manganese ion to produce a strong visible color that changes in response to nucleic acid amplification. This detection approach is easily quantitated with absorbance, rapidly and clearly visible by eye, robust to sample effects, and notably compatible with both isothermal and PCR amplification. Nucleic acid amplification and molecular diagnostic methods are being used in an increasing number of novel applications and settings, and the ability to reliably and sensitively detect them without the need for additional instrumentation will enable even more access to these powerful techniques.
“…Moreover, its applications extend to forensic sciences because of the rapid screening and on‐site monitoring properties of the integrated ME systems that enable its use in crime scene investigations [65, 66]. Such applications involve forensic genotyping [66, 67], analysis of illicit drugs [68], separation of explosive residues [69], and forensic screening of adulterations in beverages [70–72]. It was also applied to the analysis of small molecules such as pharmaceutical compounds [73–78], amino acids [75, 79, 80], environmental contaminants [81–83], and specific biomarkers [84–87].…”
Section: Microchip Electrophoresis For Analysis Of Pathogensmentioning
Life‐threatening diseases, such as hepatitis B, pneumonia, tuberculosis, and COVID‐19, are widespread due to pathogenic bacteria and viruses. Therefore, the development of highly sensitive, rapid, portable, cost‐effective, and selective methods for the analysis of such microorganisms is a great challenge. Microchip electrophoresis (ME) has been widely used in recent years for the analysis of bacterial and viral pathogens in biological and environmental samples owing to its portability, simplicity, cost‐effectiveness, and rapid analysis. However, microbial enrichment and purification are critical steps for accurate and sensitive analysis of pathogenic bacteria and viruses in complex matrices. Therefore, we first discussed the advances in the sample preparation technologies associated with the accurate analysis of such microorganisms, especially the on‐chip microfluidic‐based sample preparations such as dielectrophoresis and microfluidic membrane filtration. Thereafter, we focused on the recent advances in the lab‐on‐a‐chip electrophoretic analysis of pathogenic bacteria and viruses in different complex matrices. As the microbial analysis is mainly based on the analysis of nucleic acid of the microorganism, the integration of nucleic acid‐based amplification techniques such as polymerase chain reaction (PCR), quantitative PCR, and multiplex PCR with ME will result in an accurate and sensitive analysis of microbial pathogens. Such analyses are very important for the point‐of‐care diagnosis of various infectious diseases.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
