Method For Isolation Of DNA Research Articles

Analysis of home dust for Staphylococcus aureus and staphylococcal enterotoxin genes using quantitative PCR.

The bacterium Staphylococcus aureus (SA) is known to induce allergic inflammatory responses, including through secreted staphylococcal enterotoxin (SE) superantigens. To quantify indoor environmental exposures to these potential allergens, which may be associated with worse asthma, we developed a method for the assessment of S. aureus and SE in home dust and applied it to a study of homes of inner-city adults with asthma. We conducted laboratory experiments to optimize sample processing and real-time PCR methods for detection and quantification of SA (femB) and SEA-D, based on published primers. We applied this method to dust and dust extract from 24 homes. We compared results from real-time PCR to culture-based results from the same homes. The bacteremia DNA isolation method provided higher DNA yield than alternative kits. Culture-based results from homes demonstrated 12 of 24 (50%) bedrooms were contaminated with S. aureus, only one of which carried a SE gene (SEC). In contrast, femB was detected in 23 of 24 (96%) bedrooms with a median of 1.1×106 gene copies detected per gram of raw dust. Prevalence and median copy number (shown in parenthesis) of SE gene detection in bedroom dust was: SEA 25% (1.4×102); SEB 63% (1.4×103); SEC 63% (1.1×103); SED 21% (1.3×102). Our culture-independent method to detect S. aureus and SE in home dust was more sensitive than our culture-based method. Prevalence of household exposure to S. aureus and SE allergens may be high among adults with asthma.

Screening for Colorectal Cancer Based on the Promoter Methylation Status of the Septin 9 Gene in Plasma Cell Free DNA

Screening for colorectal cancer is widely considered a cost effective intervention with strong evidence supporting mortality reduction in the screened population. Despite this, global screening rates remain low, even in developed countries. Blood based screening tests have the potential to overcome resistance to screening, thereby increasing overall participation, and saving lives. Here we review the development of a recently US FDA approved blood based epigenetic screening test for colorectal cancer. The Epi proColon test is based on the Septin 9 (SEPT9) gene promoter methylation status measured in cell free DNA from plasma. While the assessment of DNA methylation has been practiced in laboratories for some time, the approved test provides a standardized and kitted method for isolation of cell free DNA from plasma, reagents and methods for bisulfite conversion and purification of converted DNA (bisDNA) in preparation for DNA methylation analysis by real time PCR. This enables broad dissemination of DNA methylation based testing to laboratories approved to perform standard molecular diagnostics. In clinical trials, the approved Epi proColon test had sensitivity for colorectal cancer of 68-72%, comparable to commonly used stool tests, at a specificity of 80-82%. The test was well received, with 99.5% of patients in a participation trial agreeing to testing, and of these, when the test was positive, 67% scheduled colonoscopy. Finally, 59% of patients who had a colonoscopy in this study had a finding requiring polypectomy or biopsy. Based on these data, the test was approved as a screening test in the US, for patients who are otherwise unscreened, a key advance for molecular diagnostics applications in the field of clinical epigenetics.

Modification of extraction method for community DNA isolation from salt affected compact wasteland soil samples

To overcome the issue of interferences by salt and compactness in release of bacterial cell required for lysis, method described by Yeates et al. (1998), was optimized for isolation of genomic material (Deoxyribo Nucleic Acid, DNA) from soil microbial community by addition of Al(NH4)SO4. Very low total viable count was observed in the samples tested and hence use of higher amount of soil is required primarily for DNA isolation from wasteland soils. The method proves itself efficient where commercially available bead beating and enzymatic lysis methods could not give isolation of any amount of community genomic DNA due to compact nature and salt concentrations present in soil.•The protocol was found efficient for soil samples with high clay content for microbial community DNA extraction.•Variation in lysis incubation and amount of soil may help with soil samples containing low microbial population.•Addition of Al(NH4)SO4 is crucial step in humic acid removal from extracted DNA samples for soil samples containing high salinity and clay particles.

Characterization of Microbial Communities in Acidified, Sulfur Containing Soils.

Over a period of three years, microbial communities in acidified soil with high sulfur content were analyzed. In soil water extracts ureolytic, proteolytic, oxidoreductive, and lipolytic activity were detected. The presented results indicate that the enzymatic activity of soil microbial communities varied considerably over time. Isolated 26 (80%) bacterial strains belonged to genus Bacillus sp. and were identified by cultivation and 16S rRNA methods. The commercially available procedures for bacterial DNA isolation from acidified soil failed, therefore a new, specific DNA isolation method was established. Ureolytic activity, detected in soil extracts as well as in isolated Bacillus sp. strains may be considered as a tool for the bioremediation of acidified soils with high sulfate content.

Optimal DNA Isolation Method for Detection of Nontuberculous Mycobacteria by Polymerase Chain Reaction.

Background:Nontuberculous mycobacteria (NTM) are a group of opportunistic pathogens and these are widely dispersed in water and soil resources. Identification of mycobacteria isolates by conventional methods including biochemical tests, growth rates, colony pigmentation, and presence of acid-fast bacilli is widely used, but these methods are time-consuming, labor-intensive, and may sometimes remain inconclusive.Materials and Methods:The DNA was extracted from NTM cultures using CTAB, Chelex, Chelex + Nonidet P-40, FTA® Elute card, and boiling The quantity and quality of the DNA extracted via these methods were determined using UV-photometer at 260 and 280 nm, and polymerase chain reaction (PCR) amplification of the heat-shock protein 65 gene with serially diluted DNA samples.Results:The CTAB method showed more positive results at 1:10–1:100,000 at which the DNA amount was substantial. With the Chelex method of DNA extraction, PCR amplification was detected at 1:10 and 1:1000 dilutions.Conclusions:According to the electrophoresis results, the CTAB and Chelex DNA extraction methods were more successful in comparison with the others as regard producing suitable concentrations of DNA with the minimum use of PCR inhibitor.

Intrapatient Functional Clonality Deconvoluted By Coupling Intracellular Flow Cytometry and Next Generation Sequencing in Human Leukemia

Leukemic clones within the same patient have unique sensitivities to drugs in vivo and may have unique capacities to engraft within xenograft models suggesting that there exist intra-patient functional clonal differences. However, methods to detect the functional differences assigned to genetically defined clones remain limited. Here, we describe a method to measure functional differences of clones within the same leukemia patient by coupling intracellular flow cytometry and next generation sequencing (NGS). We hypothesize that functionally distinct clones can be inferred by stimulating cells with cytokines, fluorescently staining with a relevant downstream marker of activation, and then isolating functionally distinct fractions by flow sorting. NGS can then digitally annotate somatic variants in sorted, functionally distinct samples that can be compared to the bulk leukemic cell population. To achieve this, we optimized a DNA isolation method that results in high-quality DNA despite originating from fixed/permeabilized cells. In this way, we annotate enrichment and de-enrichment of variants upon stimulation and infer the functional clonality of any given sample.To provide proof-of-concept, we explored the well-established relationship between Chronic Myelmonocytic Leukemia (CMML) and GMCSF. CMML cells are uniquely hypersensitive to GMCSF and simultaneously have a well-established mutational composition that can be annotated by sequencing only 49 genes. This allowed us to leverage an amplicon-based enrichment panel that employs emulsion PCR to achieve reproducible library preparation with 5 ng of input DNA hence bypassing the need for whole genome amplification.We tested our methodology by mixing two cell lines whose response to GMCSF was known and somatic variants had been annotated a priori. K562 (non-GMCSF responsive) and THP-1 (GMCSF responsive) leukemic cells were mixed at 1:1 and then stimulated with GMCSF. The resultant cells were stained with anti-pSTAT5 and cell sorting isolated positive and negative fractions. Unstimulated mixed cells and each positive and negative fraction was sequenced and variant allele fractions (VAF) was compared to unstimulated bulk (Figure 1A). To quantitate the change in VAF, we reasoned that summing the difference in VAF of unsorted/pSTAT5+ and unsorted/pSTAT5- populations would yield the most informative composite value as it would contain information about VAF difference for each mutation in both the GMCSF stimulated and GMCSF unstimulated fractions. Using this method, we found that 100% of THP1 and K562 variants were enriched in the pSTAT5+ and pSTAT5- fractions, respectively (Figure 1B). Receiver Operator Curves (ROC) demonstrated that the data functionally discriminated mixed THP-1 and K-562 cells with an AUC of 0.9868 (p<0.0001) (Figure1C). We additionally performed serial dilutions of THP-1 to K562 cell mixtures and demonstrated cell number dependent recovery of THP-1 variants upon stimulation with GMCSF.Next we reasoned that somatic mutations should be uniquely augmented by GMCSF stimulation making it possible for somatic variant identification. To test this, we sequenced 8 CMML bone marrow mononuclear cells evaluated in the same way as above. We additionally sorted CD3+ cells as germline controls to identify somatic mutations. Using our 49-gene panel, we identified a total of 35 somatic variants and 160 germline variants. ROC curve analysis confirmed that our assay was capable of discriminating germline from somatic mutations with an AUC of 0.9388 (p<0.001).In a representative CMML case, we counterstained with CD33 to isolate myeloid progenitors and inferred a functionally distinct clone that was hypersensitive to GMCSF and uniquely carried a JAK2 and PTPN11 mutation that was obscured by bulk leukemia sequence (Figure 2). This inference was orthogonally validated by sequencing individual colonies from the same case grown under GMCSF conditions (Figure 3). Further validation is ongoing comparing mutations identified at engraftment of cells differentially xenografted in NSG and NSGS mice that differ only in their production of human cytokines. Taken together, we describe a novel method to annotate functional differences among mutationally-defined populations and identify functionally distinct clones in primary leukemia samples. [Display omitted] [Display omitted] [Display omitted] DisclosuresKomrokji:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Speakers Bureau.

A pluripotent approach

A combination of protein and DNA isolation methods expands our grasp of cellular reprogramming.

Komparasi Metode Isolasi DNA Patogen Antraknosa dan Bulai untuk Deteksi PCR

Polymerase chain reaction (PCR) is an important tool for detection, identification and monitoring of quarantine pests in Indonesia. DNA isolation method from target organism is an important step to provide adequate DNA template for performing PCR. Objective of the research was to compare conventional, commercial kit, FTA-card and its modification methods of DNA isolation to be used in PCR detection for Colletotrichum acutatum and Peronosclerospora sorghi from chili and maize, respectively. DNA obtained from various isolation methods were measured using UV-vis nanodrop-spectrophotometry. DNA amplification was performed using DNA concentration of 15 ng µL-1 from each isolation method with gradual primer concentrations of 0.4; 0.6; 0.8; and 1.0 mM. The highest concentration of DNA was achieved with conventional methods for C. acutatum from pure culture and P. sorghi from maize leaf. Best DNA purity was obtained from isolation method using commercial kit for C. acutatum from infected fruit (1.94) and from conventional method for C. acutatum from pure culture (1.91). The highest total yield of isolated DNA was achieved by modified FTA-card for C. acutatum from pure culture. In general DNA amplification using various primer concentration gave positive results although DNA bands intensity was varied from faint to very bright. Furthermore PCR optimization using the best primer concentration from previous reaction showed that all DNA templates resulted in thick and bright DNA bands.

Comparison of DNA extraction methods for meat analysis.

Preventing adulteration of meat and meat products with less desirable or objectionable meat species is important not only for economical, religious and health reasons, but also, it is important for fair trade practices, therefore, several methods for identification of meat and meat products have been developed. In the present study, ten different DNA extraction methods, including Tris-EDTA Method, a modified Cetyltrimethylammonium Bromide (CTAB) Method, Alkaline Method, Urea Method, Salt Method, Guanidinium Isothiocyanate (GuSCN) Method, Wizard Method, Qiagen Method, Zymogen Method and Genespin Method were examined to determine their relative effectiveness for extracting DNA from meat samples. The results show that the salt method is easy to perform, inexpensive and environmentally friendly. Additionally, it has the highest yield among all the isolation methods tested. We suggest this method as an alternative method for DNA isolation from meat and meat products.

OPTIMIZATION OF DNA EXTRACTION METHODS FROM BIOLOGICAL MATERIALS OF HONEY BEES IN A DIFFERENT METAMOTPHOSIS PHASE

The aim of the research – adaptation, optimization and using of existing DNA extraction methods from bees’ biological material with the reagent «Chelex-100" under complex economic conditions of native laboratories, which will optimize labour costs and improve the economic performance of DNA extraction protocol. Materials and methods. In order to conduct the research the samples of honey bees’ biological material: queen pupae exuviae, larvae of drone brood, some adult bees’ bodies (head and thorax) were selected. Bowl and drone brood were obtained from the experimental bee hives of Institute of Apiculture nd. a. P. I. Prokopovich of NAAS. DNA extraction from biosamples of Apis mellifera ssp. was carried out using «Chelex-100®» ion exchange resin in different concentrations and combinations. Before setting tests for determination of quantitative and quality indexes, dilution of DNA samples of the probed object was conducted in ratio 1:40. The degree of contamination with protein and polysaccharide fractions (OD 260/230), quantitative content of DNA (OD 260/280) in the extracted tests were conducted using spectrophotometer of «Biospec – nano» at the terms of sample volume in 2 µl and length of optical way in 0,7 mm [7]. Verification of DNA samples from biological material of bees, isolated by «Chelex-100®», was conducted after cold keeping during 24 hours at 20°C using PСR with primaries to the fragment of gene of quantitative trait locus (QTL) Sting-2 of next structure [8]: 3' – CTC GAC GAG ACG ACC AAC TTG – 5’; 3' – AAC CAG AGT ATC GCG AGT GTT AC – 5’ Program of amplification: 94 °C – 5 minutes – 1 cycle; 94 °C – 1 minute, 57°C – 1 minute, 72 °C – 2 minutes – 30 cycles; elongation after 72°C during 2 minutes – 1 cycle. The division of obtained amplicons was conducted by gel electrophoresis at a low current – 7 µÀ, in 1,5 % agarose gel (Sigma ®) in TAE buffer [7]. The results. At the time of optimization of DNA isolation methods, according to existing methods of foreign experts, it was found optimal volume of ion exchange resin solution was in the proposed concentration: instead of 60 µl of solution used 120 µl of «Chelex-100®», time of incubation was also amended from 30 minutes to 180 minutes [9]. The use of the author's combination of method «Chelex-100®» with lysis enzymes, proteinase K and detergents (1M dithiothreitol), as time of incubation was also amended, which was reduced to 180 minutes instead of the proposed 12 hours [10]. Changes in quality characteristics of obtained DNA in samples after reduction in incubation time were not found. Conclusions. The most economical method of DNA isolation from bees’ biological material is 20% solution of «Chelex-100» ion exchange resin with the duration of the incubation period of 180 minutes. It should also be noted that the best results can be obtained from exuviae, selected immediately after the queen’s exit from bowl, that reduces the likelihood of DNA molecules destruction under the influence of nucleases activation, but not later than 12 hours from release using the technology of isolated obtain of queens.

Comparative assessment of methods for metagenomic DNA isolation from soils of different crop growing fields.

The isolation of good quality metagenomic DNA from diverse soil, in appreciable amount, is a prerequisite for metagenomics. The availability of commercial kits for isolation of genomic DNAs from soil has drastically expedited the application of metagenomics approach for identifying novel sources of industrially important enzymes. The quantitative and qualitative assessment of metagenomic DNA isolated using either the manual method or the kit-based method should be performed prior to its use in downstream applications. The metagenomic DNA isolated from six different soil samples, using three methods, were analyzed in terms of yield, quality and downstream application as template for PCR amplification. The yield of DNA was approximately 3.52, 7.35, and 232.42 μg of DNA per gram of soil sample for the kit-based method, kit-modified method, and manual method, respectively. The manual method seems to be promising based on better yield and lesser humic acid content than the other two methods. The maximum yield was obtained in the soil collected from teak forest with all the three methods, indicating maximum microbial content and diversity. Furthermore, in terms of its suitability as template DNA for PCR amplification using 16S RNA primer, all methods are equally well. Thus, comparative assessment of three methods revealed suitability of manual method based on DNA yield and humic acid content, which could be important for many downstream applications like library preparations during metageomics approach.

DNA recovery from microhymenoptera using six non-destructive methodologies with considerations for subsequent preparation of museum slides.

Because of the tiny size of microhymenoptera, successful morphological identification typically requires specific mounting protocols that require time, skills, and experience. Molecular taxonomic identification is an alternative, but many DNA extraction protocols call for maceration of the whole specimen, which is not compatible with preserving museum vouchers. Thus, non-destructive DNA isolation methods are attractive alternatives for obtaining DNA without damaging sample individuals. However, their performance needs to be assessed in microhymenopterans. We evaluated six non-destructive methods: (A) DNeasy® Blood & Tissue Kit; (B) DNeasy® Blood & Tissue Kit, modified; (C) Protocol with CaCl2 buffer; (D) Protocol with CaCl2 buffer, modified; (E) HotSHOT; and (F) Direct PCR. The performance of each DNA extraction method was tested across several microhymenopteran species by attempting to amplify the mitochondrial gene COI from insect specimens of varying ages: 1 day, 4 months, 3 years, 12 years, and 23 years. Methods B and D allowed COI amplification in all insects, while methods A, C, and E were successful in DNA amplification from insects up to 12 years old. Method F, the fastest, was useful in insects up to 4 months old. Finally, we adapted permanent slide preparation in Canada balsam for every technique. The results reported allow for combining morphological and molecular methodologies for taxonomic studies.

식품으로부터 식중독 세균 검출을 위한 Real-time PCR에 적합한 DNA 추출 방법 비교

This study was conducted to find out the most suitable DNA isolation methods for PCR detection of foodborne pathogens. Four DNA isolation methods including Universal Genomic DNA Extraction Kit (TaKaRa), PrepMan Ultra (Applied Biosystems), boiling method and alkaline lysis method (w/PEG) were tested and compared. The Universal Genomic DNA Extraction kit (TaKaRa) was considered as the more efficient isolation method for Escherichia coli O157:H7 and Staphylococcus aureus in lettuce, fish and beef. Meanwhile to detect the foodborne pathogens directly from foods without enrichment, the four different buffers such as double-distilled water, saline, glycine-saline, glycine-saline with Tween-20 and beef extract were also evaluated. As a result, saline was more suitable buffer for E. coli O157:H7. And double-distilled water was more suitable buffer than saline for S. aureus, respectively

Scale samples from Temminck’s ground pangolin (Smutsia temminckii): a non-invasive source of DNA

Non-invasive sampling aims to obtain suitable samples without causing harm to the study organism, thus making it a more preferred sampling technique. Molecular methods have advanced in such a way that quality DNA can be obtained from less invasive mammal samples. Various PCR enhancing techniques have also been developed to aid in amplification of low quality DNA samples, to produce reliable results that can be used to monitor populations and species or for forensic applications. Temminck’s ground pangolin is one of the few mammals to be covered in scales. In this study, we attempt to identify the most appropriate DNA isolation and PCR methods as well as determine whether PCR additives could be used to improve isolation of DNA and downstream amplification of mitochondrial DNA, from scale samples collected from these pangolins. In this study, it was determined that several different methods are required in order to successfully amplify DNA, and a decision tree rather than a single method should be followed.

An improved method of DNA purification from secondary metabolites rich medicinal plants using certain chaotropic agents

The presented work describes good quality DNA isolation method from mature leaves of some medicinally important plant species, viz. Asparagus racemosus, Withania somnifera, Abrus precatorius, Commiphora wightii and Carissa carandas. These plants hold immense medicinal values due to presence of certain secondary metabolites like polyphenols, terpenes, flavonoids, alkaloids, gums, resins, etc. Although these metabolites are accountable for important medicinal properties and authorize these plants to precedence over others, the same compounds disappoint the researcher while isolating high quality DNA. To overcome this problem, we propose a simple method in which DNA is adroitly bounded to diatomaceous earth in a solution of different chaotropic agent and alienated from intrusive compounds. Presented method affirms that secondary products, along with polysaccharides and proteins, can be perceptibly reduced by using silica matrix along with chaotropic agents. The described method is fast, simple and highly reliable for the isolation of DNA from obstinate plant species.

Comparison of two silica-based extraction methods for DNA isolation from bones

One of the most demanding DNA extractions is from bones and teeth due to the robustness of the material and the relatively low DNA content. The greatest challenge is due to the manifold nature of the material, which is defined by various factors, including age, storage, environmental conditions, and contamination with inhibitors. However, most published protocols do not distinguish between different types or qualities of bone material, but are described as being generally applicable. Our laboratory works with two different extraction methods based on silica membranes or the use of silica beads. We compared the amplification success of the two methods from bone samples with different qualities and in the presence of inhibitors. We found that the DNA extraction using the silica membrane method results an in higher DNA yield but also in a higher risk of co-extracting impurities, which can act as inhibitors. In contrast the silica beads method shows decreased co-extraction of inhibitors but also less DNA yield. Related to our own experiences it has to be considered that each bone material should be reviewed independently regarding the analysis and extraction method. Therefore, the most ambitious task is determining the quality of the bone material, which requires substantial experience.

A rapid method for isolation of genomic DNA from food-borne fungal pathogens.

Food contaminated with fungal pathogens can cause extremely harmful effects to human even when present in low concentrations. Researchers now pay more attention towards rapid DNA extraction for the quick screening, which is highly demanded in diverse research field. Molecular description of many fungal species is identified by different molecular characteristics. Hence, the efficient isolation of genomic DNA and amplification using PCR is a prerequisite for molecular characterization. Here, we used an improved Sodium dodecyl sulfate-Cetyltrimethyl ammonium bromide-Chloroform-isoamyl alcohol method by combining Sodium dodecyl sulfate with cetyl methylammonium bromide without addition of proteinase K, RNase K, and β-mercaptoethanol. To analyze the quality of recovered DNA, this method was compared with the other four routine methods. The present method has been chosen in the study as a preferred method because of easy adaptation to routine laboratories/food industries considering its rapid, sensitivit,y and cost effectiveness involved in the method.

Development of EST Intron-Targeting SNP Markers for Panax ginseng and Their Application to Cultivar Authentication.

Panax ginseng is one of the most valuable medicinal plants in the Orient. The low level of genetic variation has limited the application of molecular markers for cultivar authentication and marker-assisted selection in cultivated ginseng. To exploit DNA polymorphism within ginseng cultivars, ginseng expressed sequence tags (ESTs) were searched against the potential intron polymorphism (PIP) database to predict the positions of introns. Intron-flanking primers were then designed in conserved exon regions and used to amplify across the more variable introns. Sequencing results showed that single nucleotide polymorphisms (SNPs), as well as indels, were detected in four EST-derived introns, and SNP markers specific to “Gopoong” and “K-1” were first reported in this study. Based on cultivar-specific SNP sites, allele-specific polymerase chain reaction (PCR) was conducted and proved to be effective for the authentication of ginseng cultivars. Additionally, the combination of a simple NaOH-Tris DNA isolation method and real-time allele-specific PCR assay enabled the high throughput selection of cultivars from ginseng fields. The established real-time allele-specific PCR assay should be applied to molecular authentication and marker assisted selection of P. ginseng cultivars, and the EST intron-targeting strategy will provide a potential approach for marker development in species without whole genomic DNA sequence information.

An efficient and simple CTAB based method for total genomic DNA isolation from low amounts of aquatic plants leaves with a high level of secondary metabolites

An efficient DNA isolation protocol specifically modified to get pure quality DNA required for molecular studieshas been reported in this paper. Some aquatic plants (Potamogeton spp., Ceratophyllum demersum and Myriophyllum spicatum) were used for the study. The protocol developed will be useful in getting high and pure DNA. Instead of using the available DNA extraction kits, this protocol can be used to get pure quality DNA, freefrom proteins and polysaccharide compounds. The absorbance rate A260/A280 was 1.92 ± 0.069 and A260/A230 was 1.73 by spectrophotometer and NanoDrop machines which showed the sample genomic DNA is pure, free from contaminant proteins and polyphenolics/polysaccharides compound. The highest concentration of DNA was 640 ± 340.58 ng/μl when measured at 260 nm. When we run on agarose gel also, the isolated DNA gave a clear and sharp band. Thus, the DNA does not need any additional purification before proceeding for molecular analysis of the isolated DNA samples. This protocol is very simple and economical which will find wide applications in genomic studies of aquatic plants.

Rapid method for DNA isolation from a tough cell wall green alga Tetraspora sp. CU2551.

Genetic studies are important to understand the complex biological system of various organisms. Some eukaryotic green organisms have tough cell wall which precludes the efficient extraction of the genetic materials. Here, we developed the method for simple and rapid isolation of high quality DNA from a green alga Tetraspora sp. CU2551. The cell homogenization procedures were combined with physical force plus heat treatment to disrupt the cell envelope of Tetraspora sp. CU2551. Without protease treatment, vortexing with glass bead for 30-105s at 70°C led to the isolation of a high purity DNA which was suitable for downstream process. The improved method was successfully developed and could be applied for the rapid isolation of DNA from other unicellular and filamentous green microalgal strains.