Rapid Extraction Methods for Organics in Soil

Author(s):  
JK Petros ◽  
GM Alsop ◽  
RA Conway
2020 ◽  
Vol 5 (2) ◽  
pp. 95 ◽  
Author(s):  
Rajashree Chowdhury ◽  
Prakash Ghosh ◽  
Md. Anik Ashfaq Khan ◽  
Faria Hossain ◽  
Khaledul Faisal ◽  
...  

To detect Post-kala-azar leishmaniasis (PKDL) cases, several molecular methods with promising diagnostic efficacy have been developed that involve complicated and expensive DNA extraction methods, thus limiting their application in resource-poor settings. As an alternative, we evaluated two rapid DNA extraction methods and determined their impact on the detection of the parasite DNA using our newly developed recombinase polymerase amplification (RPA) assay. Skin samples were collected from suspected PKDL cases following their diagnosis through national guidelines. The extracted DNA from three skin biopsy samples using three different extraction methods was subjected to RPA and qPCR. The qPCR and RPA assays exhibited highest sensitivities when reference DNA extraction method using Qiagen (Q) kit was followed. In contrast, the sensitivity of the RPA assay dropped to 76.7% and 63.3%, respectively, when the boil & spin (B&S) and SpeedXtract (SE) rapid extraction methods were performed. Despite this compromised sensitivity, the B&S-RPA technique yielded an excellent agreement with both Q-qPCR (k = 0.828) and Q-RPA (k = 0.831) techniques. As expected, the reference DNA extraction method was found to be superior in terms of diagnostic efficacy. Finally, to apply the rapid DNA extraction methods in resource-constrained settings, further methodological refinement is warranted to improve DNA yield and purity through rigorous experiments.


2019 ◽  
Author(s):  
Rajashree Chowdhury ◽  
prakash ghosh ◽  
Md. Anik Ashfaq Khan ◽  
Faria Hossain ◽  
Khaledul Faisal ◽  
...  

Abstract Introduction Post kala-azar dermal leishmaniasis (PKDL) usually develops as sequelae of visceral leishmaniasis (VL) and can manifest in multiple dermatological forms. Since PKDL patients harbor Leishmania donovani parasites and can potentially trigger inter-epidemic transmission of the disease, the success of kala-azar elimination programme could be jeopardized by these cases. Although several molecular methods with promising diagnostic efficacy have been developed to detect PKDL cases, albeit complicated and expensive DNA extraction methods limit their application in resource poor settings. To address this, in comparison to a reference DNA extraction method (Qiagen), we evaluated two rapid DNA extraction methods and determined their impact on the detection of the parasite DNA using our newly developed recombinase polymerase amplification (RPA) assay.Methods Thirty suspected PKDL cases were enrolled after diagnosis by clinical examination and a positive rk39 strip test. DNA was extracted from three skin biopsy samples using either a spin column-based method (Qiagen) or one of two rapid DNA extraction methods, (Boil & Spin (B&S) and SpeedXtract (SE)). RPA and qPCR were subsequently performed with the extracted samples to detect L. donovani DNA.Results Using DNA extracted by Qiagen method, the qPCR and RPA assays exhibited sensitivities of 86.7% and 93.3% respectively. In contrast, the sensitivity of RPA assay dropped to 76.7% and 63.3%, respectively, when the B&S and SE rapid extraction methods were performed. Despite this compromised sensitivity, B&S-RPA technique yielded an excellent agreement with both Q-qPCR (k = 0.828) and Q-RPA (k =0.831) techniques. Moreover, SE-RPA showed good agreement with Q-qPCR (k = 0.755), Q-RPA (k =0.692) and B&S-RPA (k =0.635) assays. As expected, with all of the three DNA extraction methods, both qPCR and RPA assay showed absolute specificity.Conclusions This study finding substantiates the superior diagnostic efficacy of Qiagen DNA extraction method over B&S and SE method in detecting LD DNA through RPA assay from skin biopsy of PKDL patients. To apply these rapid DNA extraction methods in resource-constrained settings, further methodological refinement is warranted to improve DNA yield and purity through rigorous experiments.


Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
F Ghavidel ◽  
MM Zarshenas ◽  
A Sakhteman ◽  
A Gholami ◽  
Y Ghasemi ◽  
...  

2010 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
M. Takács ◽  
Gy. Füleky

The Hot Water Percolation (HWP) technique for preparing soil extracts has several advantages: it is easily carried out, fast, and several parameters can be measured from the same solution. The object of this study was to examine the possible use of HWP extracts for the characterization of soil organic matter. The HPLC-SEC chromatograms, UV-VIS and fluorescence properties of the HWP extracts were studied and the results were compared with those of the International Humic Substances Society (IHSS) Soil Humic Acid (HA), IHSS Soil Fulvic Acid (FA) and IHSS Suwannee Natural Organic Matter (NOM) standards as well as their HA counterparts isolated by traditional extraction methods from the original soil samples. The DOM of the HWP solution is probably a mixture of organic materials, which have some characteristics similar to the Soil FA fractions and NOM. The HWP extracted organic material can be studied and characterized using simple techniques, like UV-VIS and fluorescence spectroscopy.


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