scholarly journals Loop-Mediated Isothermal Amplification (LAMP) Method for the Rapid Identification of Dendrobium officinale

Author(s):  
Lu Yang ◽  
Hua Zhou ◽  
Huili Lai ◽  
Fei Fu ◽  
Wenru Wu

Background: Dendrobium officinale is not only an ornamental plant, but also a valuable medicinal herb that is both effective and widely used in traditional Chinese medicine. However, distinguishing D. officinale from other Dendrobium species is usually a difficult task that need much time and complex technologies due to their very similar external morphologies. The aim of this study is to develop a fast, even on-spot approach to identify D. officinale. Methods: We used DNA barcode-based loop-mediated isothermal amplification (LAMP) method with species-specific LAMP primers targeting the internal transcribed spacer (ITS) region of the rDNA of D. officinale. LAMP reaction time and temperature were optimized and the specificity and sensitivity of LAMP species-specific primers were assessed. Results: This technique showed a high specificity and sensitivity to amplify the genomic DNA of D. officinale and allowed for rapid amplification (within 40 min) of the ITS region under a constant and mild temperature range of 65 °C without using thermocyclers. Besides, by using SYBR® Green I dye as the color developing agent, the color change was easily observed with naked eye. Reaction mixture containing DNA of D. officinale changed from orange to green, while the other Dendrobium species and the negative control retained original orange color. The specificity of this LAMP-based method was confirmed by testing 17 samples of D. officinale and 32 adulterant samples from other Dendrobium species. Conclusions: This LAMP-based rapid identification method does not require expensive equipment or specialized techniques and can be used in field surveys for accurate and fast on site identification.

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Zhang Tie ◽  
Wang Chunguang ◽  
Wei Xiaoyuan ◽  
Zhao Xinghua ◽  
Zhong Xiuhui

To develop a rapid detection method ofStaphylococcus aureususing loop-mediated isothermal amplification (LAMP), four specific primers were designed according to six distinct sequences of thenucgene. In addition, the specificity and sensitivity of LAMP were verified and compared with those of PCR. Results showed that the LAMP reaction was completed within 45 min at 62.5°C, and ladder bands were appeared in LAMP products analyzed by gel electrophoresis. After adding 1x SYBR Green l, the positive reaction tube showed green color and the negative reaction tube remained orange, indicating that the LAMP has high specificity. The minimal detectable concentration of LAMP was1×102 CFU/mL and that of PCR was1×104 CFU/mL, indicating that the LAMP was 100 times more sensitive than the PCR. The LAMP method for detection ofStaphylococcus aureushas many advantages, such as simple operation, high sensitivity, high specificity, and rapid analysis. Therefore, this method is more suitable for the rapid on-site detection ofStaphylococcus aureus.


2011 ◽  
Vol 47 (No. 4) ◽  
pp. 140-148 ◽  
Author(s):  
N. Rostamkhani ◽  
A. Haghnazari ◽  
M. Tohidfar ◽  
A. Moradi

In an attempt to speed up the process of screening of transgenic cotton (G. hirsutum L.) plants, a visual and rapid loop-mediated isothermal amplification (LAMP) assay was adopted. Genomic DNA was extracted from fresh leaf tissues of T<sub>2</sub> transgenic cotton containing chitinase (chi) and cry1A(b) genes. Detection of genes of interest was performed by polymerase chain reaction (PCR), LAMP and real-time PCR methods. In LAMP assay the amplification was performed after 30 min at 65&deg;C when loop primers were involved in the reaction. The involvement of loop primers decreased the time needed for amplification. By testing serial tenfold dilutions (10<sup>&ndash;1</sup> to 10<sup>&ndash;8</sup>) of the genes of interest, the detection sensitivity of LAMP was found to be 100-fold higher than that of PCR. The rapid DNA extraction method and LAMP assay can be performed within 30 min and the derived LAMP products can be directly observed as visually detectable based on turbidity in the reaction tube. The accuracy of LAMP method in the screening of transgenes was confirmed by PCR and real-time PCR. The developed method was efficient, rapid and sensitive in the screening of cotton transgenic plants. This method can be applied to any other crops.


2020 ◽  
Vol 48 (1) ◽  
Author(s):  
Hiroka Aonuma ◽  
Itoe Iizuka-Shiota ◽  
Tokio Hoshina ◽  
Shigeru Tajima ◽  
Fumihiro Kato ◽  
...  

Abstract Background Monitoring both invasion of Zika virus disease into free countries and circulation in endemic countries is essential to avoid a global pandemic. However, the difficulty lies in detecting Zika virus due to the large variety of mutations in its genomic sequence. To develop a rapid and simple method with high accuracy, reverse transcription-loop-mediated isothermal amplification (RT-LAMP) was adopted for the detection of Zika virus strains derived from several countries. Results Common primers for RT-LAMP were designed based on the genomic sequences of two standard Zika strains: African lineage, MR-766, and Asian lineage, PRVABC59. RT-LAMP reactions using a screened primer set, targeting the NS3 region, detected both Zika virus strains. The minimum detectable quantity was 3 × 10−2 ng of virus RNA. Measurable lag of reaction times among strains was observed. The RT-LAMP method amplified the target virus sequence from the urine and serum of a patient with a travel history in the Caribbean Islands and also provided a prediction about which lineage of Zika virus strain was present. Conclusions The RT-LAMP method using a well-optimized primer set demonstrated high specificity and sensitivity for the detection of Zika virus strains with a variety in genomic RNA sequences. In combination with the simplicity of LAMP reaction in isothermal conditions, the optimized primer set established in this study may facilitate rapid and accurate diagnosis of Zika fever patients with virus strain information.


Author(s):  
Maryam ARFAATABAR ◽  
Narjes NOORI GOODARZI ◽  
Davoud AFSHAR ◽  
Hamed MEMARIANI ◽  
Ghasem AZIMI ◽  
...  

  Background: Mycoplasma pneumoniae is a common cause of community-acquired pneumonia (CAP) worldwide, especially among children and debilitated populations. The present study aimed to investigate a loop-mediated isothermal amplification (LAMP) technique for rapid detection of M. pneumoniae in clini-cal specimens collected from patients with pneumonia. Methods: Throat swabs were collected from 110 outpatients who suffered from pneumonia. Throat swab samples were obtained from patients referred to the hospital outpatient clinics of Tehran University hospitals, Iran in 2017. The presence of M. pneumoniae in the clinical specimens was evaluated by LAMP, PCR and culture methods. Sensitivity and specificity of the LAMP and PCR assays were also determined. Results: Out of 110 specimens, LAMP assay detected M. pneumoniae in 35 specimens. Detection limit of the LAMP assay was determined to be 33fg /μL or ~ 40 genome copies/reaction. Moreover, no cross-reaction with genomic DNA from other bacteria was observed. Only 25 specimens were positive by the culture method. The congruence between LAMP assay and culture method was ‘substantial’ (κ=0.77). Specificity and sensitivity of LAMP assay were 88.2%, 100% in compare with culture. However, the con-gruence between LAMP assay and PCR assay was ‘almost perfect’ (κ=0.86). Specificity and sensitivity of LAMP assay were 92.5%, 100% in compare with PCR. Conclusion: Overall, the LAMP assay is a rapid and cost-efficient laboratory test in comparison to other methods including PCR and culture. Therefore, the LAMP method can be applied in identification of M. pneumoniae isolates in respiratory specimens.


2013 ◽  
Vol 16 (1) ◽  
pp. 131-133 ◽  
Author(s):  
Ł. Adaszek ◽  
M. Jankowska ◽  
M. Kalinowski ◽  
T. Banach ◽  
D. Wułupek ◽  
...  

Abstract The aim of this study was to use a rapid and easy DNA-based test, the loop-mediated isothermal amplification (LAMP), for diagnosis of Babesia canis canis infections in dogs. 10 DNA samples of 18S RNA-A and 10 DNA samples of 18S RNA-B of B. canis canis were used in the study. LAMP method could successfully detect DNA in all examined samples down to 0.1 pg dilution. Obtained results suggest that this method has high specificity and sensitivity and can be applied in analytical laboratories in diagnosis of canine babesiosis.


Author(s):  
Amol Kokane ◽  
Sunil Kokane ◽  
Ashish Warghane ◽  
Mrugendra G Gubyad ◽  
Ashwani Kumar Sharma ◽  
...  

Indian citrus ringspot virus (ICRSV) is a devastating pathogen that has a particularly deleterious effect on the ‘Kinnow mandarin’, a commercial citrus crop cultivated in the north-west of India. ICRSV belongs to the Mandarivirus genus within the family of Alphaflexiviridae and has a positive sense single-stranded RNA (ssRNA) genome consisting of six open reading frames (ORFs). Severe cases of ICRSV result in a significant reduction in both the yield and quality of crops. Consequently, there is an urgent need to develop methods to detect ICRSV in an accurate and timely manner. Current methods involve a two-step reverse transcriptase-polymerase chain reaction (RT-PCR) that is time-consuming. Here, we describe a novel, one-step, reverse transcription-loop-mediated isothermal amplification (RT-LAMP) method for the sensitive and rapid detection of ICRSV. The RT-LAMP assay was standardized by designing and testing four different primers that targeted the coat protein gene of ICRSV. Amplification results were visualized by a color change after addition of SYBR Green I. The standardized RT-LAMP assay was highly specific and successfully detected all 35 ICRSV isolates tested from the Punjab and Haryana states of India. Furthermore, there was no cross-reaction with 17 isolates of five other citrus pathogens that are common in India. ICRSV-RT-LAMP assay developed in the present study is a simple, rapid, sensitive, and specific, technique. Moreover, the assay consists of only a single step and is more cost-effective than existing methods. This represents the first application of RT-LAMP for the detection of ICRSV. Our RT-LAMP assay is a powerful tool for the detection of ICRSV and will be particularly useful for large scale indexing of field samples in diagnostic laboratories, nurseries, and for quarantine applications.


2021 ◽  
Vol 15 (1) ◽  
pp. e0008996
Author(s):  
Thoko Flav Kapalamula ◽  
Jeewan Thapa ◽  
Mwangala Lonah Akapelwa ◽  
Kyoko Hayashida ◽  
Stephen V. Gordon ◽  
...  

Bovine tuberculosis (TB) caused by Mycobacterium bovis is a significant health threat to cattle and a zoonotic threat for humans in many developing countries. Rapid and accurate detection of M. bovis is fundamental for controlling the disease in animals and humans, and for the proper treatment of patients as one of the first-line anti-TB drug, pyrazinamide, is ineffective against M. bovis. Currently, there are no rapid, simplified and low-cost diagnostic methods that can be easily integrated for use in many developing countries. Here, we report the development of a loop-mediated isothermal amplification (LAMP) assay for specific identification of M. bovis by targeting the region of difference 4 (RD4), a 12.7 kb genomic region that is deleted solely in M. bovis. The assay's specificity was evaluated using 139 isolates comprising 65 M. bovis isolates, 40 M. tuberculosis isolates, seven M. tuberculosis complex reference strains, 22 non-tuberculous mycobacteria and five other bacteria. The established LAMP detected only M. bovis isolates as positive and no false positives were observed using the other mycobacteria and non-mycobacteria tested. Our LAMP assay detected as low as 10 copies of M. bovis genomic DNA within 40 minutes. The procedure of LAMP is simple with an incubation at a constant temperature. Results are observed with the naked eye by a color change, and there is no need for expensive equipment. The established LAMP can be used for the detection of M. bovis infections in cattle and humans in resource-limited areas.


Sign in / Sign up

Export Citation Format

Share Document