• Journal of Life Science
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• v.14 no.2
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• pp.296-300
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• 2004

We investigated feasibility of using the formalin-fixed and paraffin-embedded tissue to study mitochondrial mutations in the case that fresh or frozen tissue, or blood samples are not available. Four paraffin blocks of muscle biopsies in Korean MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) patients were chosen. Total DNA was extracted from these blocks for PCR/RFLP analysis, and sequencing was performed to study the most common mutation, A to G transition at nucleotide position 3243 underlying MELAS in the mitochondrial tRN $A^{Leu(UUR)}$ gene. We could identify the A to G mutation at nt.3243 in three MELAS patients. Our results show that the mitochondrial genome of our paraffin blocks is presumably in good condition. Our results are in accordance with the previous findings by other investigators that PCR allows molecular genetic analysis of paraffin-embedded tissues stored in most histopathology laboratories.s.

• Biomedical Science Letters
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• v.28 no.4
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• pp.298-306
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• 2022

Pathological tissue fixation using formalin has been widely used for histological samples in many hospitals and institutions. In general, formalin fixatives were either manufactured in laboratories or purchased commercially because of the risks and environmental concerns of handling organic compounds. In this study, the efficacy of three kinds of commercially purchased and one laboratory-made formalin fixative was compared in the PCR-based molecular diagnosis using the extracted DNA from formalin-fixed paraffin-embedded (FFPE) tissues. The quality of extracted DNA from FFPE tonsil tissues with four kinds of formalin solutions was evaluated, and PCR for beta-globin gene and microsatellite instabilities (MSI) tests for pentaplex panel markers were performed using the extracted DNA. There was no difference in PCR and MSI tests as molecular diagnoses regardless of the types of formalin used in this study. However, the total amount and average length of double-stranded DNA extracted from FFPE tonsil tissue showed significant differences according to the type of formalin fixative. Optimized formalin fixatives and methods for DNA extraction might be sophisticated to extract good quality DNA from the small size of specific tissue samples. Further studies are needed to select the most effective formalin fixative for histology and molecular pathology using human FFPE tissues.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.27-27
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• 2003

Porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV) infections are considered difficult to distinguish clinically and histopathologically. Prompt differentiation between PEDV- and TGEV-associated enteritis would greatly facilitate the management of disease in countries where PEDV and TGEV are epizootic. Rapid differential diagnosis and treatment are crucial to reducing mortality and morbidity from PEDV- and TGEV-induced enteritis in piglets. The objective for this study was to develop a protocol to differentiate between PEDV and TGEV directly from formalin-fixed, paraffin-embedded tissue, using a multiplex reverse transcription-nested polymerase chain reaction (RT-nPCR) assay. (omitted)

• Korean Journal of Veterinary Research
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• v.33 no.2
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• pp.269-275
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• 1993

Tissue distribution of RHDV in rabbits were examined by immunofluorescence and ABC methods. Tissues including liver, spleen, kidneys, lungs and brain were frozen, cut in a crycut, and fixed in 10% buffered formalin, embedded in paraplast, and cut $5{\sim}7{\mu}m$ thickness. Sections were immunostained Tissue distribution of RHDV in rabbits were examined by immunofluorescence and ABC methods. Tissues including liver, spleen, kidneys, lungs and brain were frozen, cut in a crycut, and fixed in 10% buffered formalin, embedded in paraplast, and cut $5{\sim}7{\mu}m$ thickness. Sections were immunostained with primary antiserum and conjugated second antibodies as recommended by manufacturer. None of the cultures tested showed virus-induced phenomena. Immunoreactive products were commonly found in the liver, in some cases there were also positive staining in the spleen and kidneys. Other organs showed weak or insignificant immunoreactions. By ABC method on the formalin-fixed, paraffin-embedded liver tissues, strong immunoreactivity was found in the periportal triad lesions and peripheral lesions of the hepatic lobules. Immunoreactive products showed diffuse fine granular in the cytoplasm of hepatocytes and sinusoidal cells. In some cells, immunoproducts marginate at the periphery of the cells. The intensive staining of the cytoplasm of infected cells allowed their exact differentiation from surrounding uninfected cells. The positive area involved coincided with histopathological lesion on serial liver sections. In conclusion, liver was proved to be a consistent target organ in RHD, and the immunoperoxidase method in the section of formalin-fixed, paraffin-embedded hepatic tissue could be broadly used for the routine diagnosis of the disease.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2733-2737
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• 2014

Objective: Molecular pathology tests are often carried for clinicopathological diagnosis and pathologists have established large collections of formalin-fixed, paraffin-embedded tissue (FFPE) banks. However, extraction of DNA from FFPE is a laborious and challenging for researchers in clinical laboratories. The aim of this study was to compare two widely used DNA extraction methods: using a QIAamp DNA FFPE kit from Qiagen and a Cobas Sample Preparation Kit from Roche, and evaluated the effect of the DNA quality on molecular diagnostics. Methods: DNA from FFPE non-small cell lung carcinoma tissues including biopsy and surgical specimens was extracted with both QIAamp DNA FFPE and Cobas Sample Preparation Kits and EGFR mutations of non-small cell lung carcinomas were detected by real-time quantitative PCR using the extracted DNA. Results and Conclusion: Our results showed that DNA extracted by QIAamp and Cobas methods were both suitable to detect downstream EGFR mutation in surgical specimens. Howover, Cobas method could yield more DNA from biopsy specimens, and gain much better EGFR mutation results.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6619-6623
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• 2013

Background:The aim of the research was to explore a cost effective, fast, easy to perform, and sensitive method for epidermal growth factor receptor (EGFR) mutation testing. Methods: High resolution melting analysis (HRM) was introduced to evaluate the efficacy of the analysis for dectecting EGFR mutations in exons 18 to 21 using formalin-fixed paraffin-embedded (FFPE) tissues and plasma free DNA from 120 patients. Results: The total EGFR mutation rate was 37.5% (45/120) detected by direct sequencing. There were 48 mutations in 120 FFPE tissues assessed by HRM. For plasma free DNA, the EGFR mutation rate was 25.8% (31/120). The sensitivity of HRM assays in FFPE samples was 100% by HRM. There was a low false-positive mutation rate but a high false-negative rate in plasma free DNA detected by HRM. Conclusions: Our results show that HRM analysis has the advantage of small tumor sample need. HRM applied with plasma free DNA showed a high false-negative rate but a low false-positive rate. Further research into appropriate methods and analysis needs to be performed before HRM for plasma free DNA could be accepted as an option in diagnostic or screening settings.

• Biomedical Science Letters
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• v.19 no.2
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• pp.153-157
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• 2013

Although culture is the gold standard method to identify mycobacteria, its use in tuberculous lymphadenitis (TBL) is limited due to formalin fixation of the submitted specimens. We evaluated the performance of quantitative real-time PCR (q-PCR) for Mycobacterium Tuberculosis (MTB) in granulomatous lymphadenitis using formalin-fixed paraffin-embedded (FFPE) tissues. From 2000 to 2010, a total number of 117 cases of lymph node samples with granulomatous inflammation which were surgically removed and fixed in formalin were studied. Hematoxylin & Eosin (H&E) and Ziehl-Neelsen-stained (ZN) slides were reviewed. qPCR using Real TB-Taq$^{(R)}$ was performed for all cases to identify Mycobacterium tuberculosis. Thirteen non-tuberculous lymphadenopathy cases were used as negative control. Cervical lymph nodes were more frequently affected (60%, 70/117) than other sites. ZN stain for acid fast bacilli was positive in 19 (16.24%) cases. qPCR for tuberculosis was positive in 92 (78.63%) cases. Caseous necrosis was found in 103 (88.03%) cases. While the ZN stain and qPCR were both negative in all control cases, the qPCR showed a significantly higher positive rate (78.63% vs. 16.24%) compared to ZN stain in histologically diagnosed TBL. Quantitative real-time PCR proves to be more sensitive than ZN stain for diagnosis of tuberculous lymphadenitis.

• Biomedical Science Letters
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• v.8 no.3
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• pp.161-165
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• 2002

Apoptosis can be difficult to detect in routine histological sections. Since extensive DNA fragmentation is an important characteristic of this process, visualization of DNA breaks could greatly facilitate the identification of apoptotic cells. Several techniques for the qualitative and quantitative detection of this process have been established; recently, an in situ nick end-labelling technique based on the detection of DNA fragmentation, which is a molecular characteristic of apoptotic cell death, was described. Applying this method to paraffin sections of rat tissues, sensitivity was observed to be inconsistently low with regard to the expected number of apoptotic cells. I describe a new modified method for formalin-fixed, paraffin-embedded tissue sections, pretense pretreatment to permeate the tissue sections that involves an TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling) is acknowledged as a method of choice in the rapid identification and quantification of the apoptotic cell fraction in paraffin tissue preparations. TUNEL was performed without apoptosis and with apopotosis samples to each of the three concentrations of proteinase K (10, 25, 40 mg/ml) pretreatments. In this study, I show that chemical pretreatments of the tissue sections in proteinase K (25 mg/ml for 15 min at room temperature) considerably enhances the sensitivity of this nick end labelling technique.

• Korean Journal of Clinical Laboratory Science
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• v.40 no.2
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• pp.113-117
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• 2008

It designed a study to examine the efficiency of DNA and RNA extraction from archival formalin-fixed, paraffin-embedded tissues using an non-heating and heating method. Archival paraffin blocks of liver, kidney, colon were randomly selected. Each paraffin block was prepared in 20 microtubes. For each paraffin blocks were tested non-heating DNA extraction to 10 microtubes and heating protocol under pH 7.0 and $100^{\circ}C$ to 10 microtubes. Evaluation of the results of DNA extraction was carried out by measuring concentration by UV spectrophotometry and then PCR amplification. DNA extraction content that non-heating method was liver $5{\pm}0.7{\mu}g/mL$, kidney $2{\pm}0.3{\mu}g/mL$, colon $6{\pm}0.4{\mu}g/mL$ and heating method was liver $12{\pm}0.6{\mu}g/mL$, kidney $7{\pm}0.5{\mu}g/mL$, colon $10.{\pm}0.3{\mu}g/mL$. Successful RNA extraction was observed, by ${\beta}$-actin amplification, in 46.7% sections for samples treated by the heating method versus 30.0% using non-heating DNA extraction. The extracted nucleic acid showed better values for samples heated at $100^{\circ}C$. Therefore heating extraction of nucleic acid is reliable, quick and efficiency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.417-424
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• 2019

Despite its superior ability to show distinct cellular morphology and for long-term storage, conventional tissue fixation by formalin has many drawback, including slower fixation, the exposure to harmful chemicals and extensive protein modification. Herein, we assessed the effects of rapid microwave-assisted tissue fixation on histological examination and on protein integrity by comparing these microwave irradiation fixated tissues with the formalin-fixed tissues. One of the paired mouse tissues (liver and kidney) was fixed in formalin and the other was fixed by using microwave irradiation in phosphate buffered saline. Each slide from the paraffin-embedded tissues was examined by H & E staining for the adequacy of fixation and by immunohistochemical staining for antigenicity in a blinded fashion. Evaluation of protein recovery and the protein quality from the fixed tissues were analyzed by the BCA method and Western blotting, respectively. The results from H & E staining and immunohistochemical staining showed that the sections obtained from microwave-fixed tissues under our experimental conditions were comparable to those of the formalin-fixed tissues except for the integrity of RBCs. Furthermore, proteins were effectively extracted from the microwave-fixed tissues with acceptable preservation of the proteins' quality. Taken together, this microwave-assisted tissue processing yields a quick fixation and better protein recovery in higher amounts, as well as the adequacy of fixation and the antigenicity being comparable to formalin-fixed tissues, and this all suggests that this new fixation technique can be applied in an environment where rapid tissue fixation is required.