A novel xylene-free deparaffinization method for the extraction of proteins from human derived formalin-fixed paraffin embedded (FFPE) archival tissue blocks

Detection and Validation of Organic Metabolites in Urine for Clear Cell Renal Cell Carcinoma Diagnosis

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) comprises the majority, approximately 70-80%, of renal cancer cases and often remains asymptomatic until incidentally detected during unrelated abdominal imaging or at advanced stages. Currently, standardized screening tests for renal cancer are lacking, which presents challenges in disease management and improving patient outcomes. This study aimed to identify ccRCC-specific volatile organic compounds (VOCs) in the urine of ccRCC-positive patients and develop a urinary VOC-based diagnostic model.

METHODS

This study involved 233 pretreatment ccRCC patients and 43 healthy individuals. VOC analysis utilized stir-bar sorptive extraction coupled with thermal desorption gas chromatography/mass spectrometry (SBSE-TD-GC/MS). A ccRCC diagnostic model was established via logistic regression, trained on 163 ccRCC cases versus 31 controls, and validated with 70 ccRCC cases versus 12 controls, resulting in a ccRCC diagnostic model involving 24 VOC markers.

RESULTS

The findings demonstrated promising diagnostic efficacy, with an Area Under the Curve (AUC) of 0.94, 86% sensitivity, and 92% specificity.

CONCLUSIONS

This study highlights the feasibility of using urine as a reliable biospecimen for identifying VOC biomarkers in ccRCC. While further validation in larger cohorts is necessary, this study's capability to differentiate between ccRCC and control groups, despite sample size limitations, holds significant promise.

Quantitative cytoarchitectural phenotyping of deparaffinized human brain tissues

Advanced 3D imaging techniques and image segmentation and classification methods can profoundly transform biomedical research by offering deep insights into the cytoarchitecture of the human brain in relation to pathological conditions. Here, we propose a comprehensive pipeline for performing 3D imaging and automated quantitative cellular phenotyping on Formalin-Fixed Paraffin-Embedded (FFPE) human brain specimens, a valuable yet underutilized resource. We exploited the versatility of our method by applying it to different human specimens from both adult and pediatric, normal and abnormal brain regions. Quantitative data on neuronal volume, ellipticity, local density, and spatial clustering level were obtained from a machine learning-based analysis of the 3D cytoarchitectural organization of cells identified by different molecular markers in two subjects with malformations of cortical development (MCD). This approach will grant access to a wide range of physiological and pathological paraffin-embedded clinical specimens, allowing for volumetric imaging and quantitative analysis of human brain samples at cellular resolution. Possible genotype-phenotype correlations can be unveiled, providing new insights into the pathogenesis of various brain diseases and enlarging treatment opportunities.

Quantitative Comparison of Deparaffinization, Rehydration, and Extraction Methods for FFPE Tissue Proteomics and Phosphoproteomics

Formalin-fixed paraffin-embedded (FFPE) tissues are suitable for proteomic and phosphoproteomic biomarker studies by data-independent acquisition mass spectrometry. The choice of the sample preparation method influences the number, intensity, and reproducibility of identifications. By comparing four deparaffinization and rehydration methods, including heptane, histolene, SubX, and xylene, we found that heptane and methanol produced the lowest coefficients of variation (CVs). Using this, five extraction methods from the literature were modified and evaluated for their performance using kidney, leg muscle, lung, and testicular rat organs. All methods performed well, except for SP3 due to insufficient tissue lysis. Heat n' Beat was the fastest and most reproducible method with the highest digestion efficiency and lowest CVs. S-Trap produced the highest peptide yield, while TFE produced the best phosphopeptide enrichment efficiency. The quantitation of FFPE-derived peptides remains an ongoing challenge with bias in UV and fluorescence assays across methods, most notably in SPEED. Functional enrichment analysis demonstrated that each method favored extracting some gene ontology cellular components over others including chromosome, cytoplasmic, cytoskeleton, endoplasmic reticulum, membrane, mitochondrion, and nucleoplasm protein groups. The outcome is a set of recommendations for choosing the most appropriate method for different settings.

Effect of cooking on structural changes in the common black bean (Phaseolus vulgaris var. Jamapa)

The cooking process is fundamental for bean consumption and to increase the bioavailability of its nutritional components. The study aimed to determine the effect of cooking on bean seed coat through morphological analyses with different microscopy techniques and image analyses. The chemical composition and physical properties of raw black bean (RBB) and cooked black bean (CBB) seeds were determined. The surface and cross-sectional samples were studied by Optical microscopy (OM), environmental scanning electron microscopy (ESEM), atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). The composition of samples showed significant differences after the cooking process. OM images and gray level co-occurrence matrix algorithm (GLCM) analysis indicated that cuticle-deposited minerals significantly influence texture parameters. Seed coat surface ESEM images showed cluster cracking. Texture fractal dimension and lacunarity parameters were effective in quantitatively assessing cracks on CBB. AFM results showed arithmetic average roughness (Ra) (121.67 nm) and quadratic average roughness (Rq) (149.94 nm). The cross-sectional ESEM images showed a decrease in seed coat thickness. The CLSM results showed an increased availability of lipids along the different multilayer tissues in CBB. The results generated from this research work offer a valuable potential to carry out a strict control of bean seed cooking at industrial level, since the structural changes and biochemical components (cell wall, lipids and protein bodies) that occur in the different tissues of the seed are able to migrate from the inside to the outside through the cracks generated in the multilayer structure that are evidenced by the microscopic techniques used.

Conservation of vCJD Strain Properties After Extraction and In Vitro Propagation of PrPSc from Archived Formalin-Fixed Brain and Appendix Tissues Using Highly Sensitive Protein Misfolding Cyclic Amplification

Three retrospective lymphoreticular tissue studies (Appendix I, II, and III) aimed to estimate the UK prevalence of variant Creutzfeldt-Jakob disease (vCJD), following exposure of the population to the bovine spongiform encephalopathy (BSE) agent, in the late 1980s and 1990s. These studies evaluated the presence of abnormal prion protein aggregates, in archived formalin-fixed paraffin-embedded (FFPE) appendectomy samples, by immunohistochemical detection. Although there was concordance in the estimated prevalence of vCJD from these studies, the identification of positive specimens from pre- and post-BSE-exposure periods in Appendix III study has raised questions regarding the nature and origin of the detected abnormal prion protein. We applied a robust and novel approach in the extraction of disease-associated prion protein (PrPSc) present in frozen and FFPE samples of brain and appendix from a patient with pathologically confirmed vCJD. The extracted material was used to seed the highly sensitive protein misfolding cyclic amplification assay (hsPMCA) to investigate the in vitro and in vivo propagation properties of the extracted abnormal prion protein. We demonstrate that PrPSc can be successfully extracted from FFPE appendix tissue and propagated in vitro. Bioassay in wild-type and gene-targeted mouse models confirmed that the extracted and amplified product is infectious and retains strain properties consistent with vCJD. This provides a highly sensitive and reliable platform for subsequent analysis of the archived FFPE appendix tissue derived from the Appendix II and III surveys, to further evaluate the nature of the abnormal PrP detected in the positive samples.

Epigenomic analysis of formalin-fixed paraffin-embedded samples by CUT&Tag

For more than a century, formalin-fixed paraffin-embedded (FFPE) sample preparation has been the preferred method for long-term preservation of biological material. However, the use of FFPE samples for epigenomic studies has been difficult because of chromatin damage from long exposure to high concentrations of formaldehyde. Previously, we introduced Cleavage Under Targeted Accessible Chromatin (CUTAC), an antibody-targeted chromatin accessibility mapping protocol based on CUT&Tag. Here we show that simple modifications of our CUTAC protocol either in single tubes or directly on slides produce high-resolution maps of paused RNA Polymerase II at enhancers and promoters using FFPE samples. We find that transcriptional regulatory element differences produced by FFPE-CUTAC distinguish between mouse brain tumors and identify and map regulatory element markers with high confidence and precision, including microRNAs not detectable by RNA-seq. Our simple workflows make possible affordable epigenomic profiling of archived biological samples for biomarker identification, clinical applications and retrospective studies.

Disease-Specific α-Synuclein Seeding in Lewy Body Disease and Multiple System Atrophy Are Preserved in Formaldehyde-Fixed Paraffin-Embedded Human Brain

Recent studies have been able to detect α-synuclein (αSyn) seeding in formaldehyde-fixed paraffin-embedded (FFPE) tissues from patients with synucleinopathies using seed amplification assays (SAAs), but with relatively low sensitivity due to limited protein extraction efficiency. With the aim of introducing an alternative option to frozen tissues, we developed a streamlined protein extraction protocol for evaluating disease-specific seeding in FFPE human brain. We evaluated the protein extraction efficiency of different tissue preparations, deparaffinizations, and protein extraction buffers using formaldehyde-fixed and FFPE tissue of a single Lewy body disease (LBD) subject. Alternatively, we incorporated heat-induced antigen retrieval and dissociation using a commercially available kit. Our novel protein extraction protocol has been optimized to work with 10 sections of 4.5-µm-thickness or 2-mm-diameter micro-punch of FFPE tissue that can be used to seed SAAs. We demonstrated that extracted proteins from FFPE still preserve seeding potential and further show disease-specific seeding in LBD and multiple system atrophy. To the best of our knowledge, our study is the first to recapitulate disease-specific αSyn seeding behaviour in FFPE human brain. Our findings open new perspectives in re-evaluating archived human brain tissue, extending the disease-specific seeding assays to larger cohorts to facilitate molecular subtyping of synucleinopathies.

Design and Fabrication of a Dual Protein-Based Trilayered Nanofibrous Scaffold for Efficient Wound Healing

Chronic wound healing is a major threat all over the world. There are currently a plethora of biomaterials-based wound dressings available for wound healing applications. In this study, a dual protein-based (silk fibroin and sericin) nanofibrous scaffold from a natural source (B.mori silkworm cocoons) with antibacterial and antioxidative properties for wound healing was investigated. An electrospun layer-by-layer silk protein-based nanofibrous scaffold was fabricated with a top layer of hydrophobic silk fibroin protein blended with polyvinyl alcohol (PVA), a middle layer of waste protein silk sericin loaded with silver(I) sulfadiazine as an antibacterial agent, and a bottom layer using silk fibroin blended with polycaprolactone (PCL). The trilayered nanofibrous scaffold with a smooth and bead-free morphology demonstrated excellent wettability, slow in vitro degradation, controlled drug release, and potent antibacterial and antioxidant properties. In vitro, the scaffold also demonstrated excellent hemocompatibility and biocompatibility. Furthermore, in vivo wound contraction, histological, and micro-CT investigations show complete wound healing and the formation of new skin tissue in a male Balb/c mouse model treated with the scaffold. The antioxidant properties of the sericin protein and SSD-based triple-layered nanofibrous scaffold protect the wound from bacterial infection and improve wound healing in a mouse model. The current study develops a dual protein-based nanofibrous scaffold with antibacterial and antioxidant properties as a promising wound dressing material.

Systematic evaluation and optimization of protein extraction parameters in diagnostic FFPE specimens

Objectives

Formalin-fixed paraffin-embedded (FFPE) tissue is the standard material for diagnostic pathology but poses relevant hurdles to accurate protein extraction due to cross-linking and chemical alterations. While numerous extraction protocols and chemicals have been described, systematic comparative analyses are limited. Various parameters were thus investigated in their qualitative and quantitative effects on protein extraction (PE) efficacy. Special emphasis was put on preservation of membrane proteins (MP) as key subgroup of functionally relevant proteins.

Methods

Using the example of urothelial carcinoma, FFPE tissue sections were subjected to various deparaffinization, protein extraction and antigen retrieval protocols and buffers as well as different extraction techniques. Performance was measured by protein concentration and western blot analysis of cellular compartment markers as well as liquid chromatography-coupled mass spectrometry (LC–MS).

Results

Commercially available extraction buffers showed reduced extraction of MPs and came at considerably increased costs. On-slide extraction did not improve PE whereas several other preanalytical steps could be simplified. Systematic variation of temperature and exposure duration demonstrated a quantitatively relevant corridor of optimal antigen retrieval.

Conclusions

Preanalytical protein extraction can be optimized at various levels to improve unbiased protein extraction and to reduce time and costs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12014-022-09346-0.

Mummified embalmed head skin: SR-FTIR microspectroscopic exploration

This case report details the examination of the skin of an Egyptian mummified head with a possible skin disorder. The head, thought to be dated in the first half of the 18th Dynasty, New Kingdom (1570-1400 BCE) belongs to the Museum of Forensic Anthropology, University of Madrid. Initial histological examination demonstrated evidence of chronic inflammation, which was confirmed by immunohistochemistry and Transmission Electron Microscopy (TEM). However, confirmation of pathology could be confounded by both the age of the specimen and the process of preservation by mummification. In this case report, Synchrotron Radiation Fourier Transform Microspectroscopy (SR-µFTIR) was used to add novel insights into embalmed mummified tissue. More precisely, FTIR is used for the first time on the specific specimens, while no other similar studies have been performed on these samples priorly. Additionally, modern skin tissue was examined too, in order to compare the amount of degradation to the mummified one. Whilst the FTIR results confirmed the results from the initial histological study, they also showed a biochemical modification of the mummified skin that could be indicative of tissue degradation. The latter was supported by comparing it to FTIR results of the modern tissue used.

A Novel Nanoproteomic Approach for the Identification of Molecular Targets Associated with Thyroid Tumors

A thyroid nodule is the most common presentation of thyroid cancer; thus, it is extremely important to differentiate benign from malignant nodules. Within malignant lesions, classification of a thyroid tumor is the primary step in the assessment of the prognosis and selection of treatment. Currently, fine-needle aspiration biopsy (FNAB) is the preoperative test most commonly used for the initial thyroid nodule diagnosis. However, due to some limitations of FNAB, different high-throughput “omics” approaches have emerged that could further support diagnosis based on histopathological patterns. In the present work, formalin-fixed paraffin-embedded (FFPE) tissue specimens from normal (non-neoplastic) thyroid (normal controls (NCs)), benign tumors (follicular thyroid adenomas (FTAs)), and some common types of well-differentiated thyroid carcinoma (follicular thyroid carcinomas (FTCs), conventional or classical papillary thyroid carcinomas (CV-PTCs), and the follicular variant of papillary thyroid carcinomas (FV-PTCs)) were analyzed. For the first time, FFPE thyroid samples were deparaffinized using an easy, fast, and non-toxic method. Protein extracts from thyroid tissue samples were analyzed using a nanoparticle-assisted proteomics approach combined with shotgun LC-MS/MS. The differentially regulated proteins found to be specific for the FTA, FTC, CV-PTC, and FV-PTC subtypes were analyzed with the bioinformatic tools STRING and PANTHER showing a profile of proteins implicated in the thyroid cancer metabolic reprogramming, cancer progression, and metastasis. These proteins represent a new source of potential molecular targets related to thyroid tumors.

Shmt2: A Stat3 Signaling New Player in Prostate Cancer Energy Metabolism

Prostate cancer (PCa) is a multifactorial disease characterized by the aberrant activity of different regulatory pathways. STAT3 protein mediates some of these pathways and its activation is implicated in the modulation of several metabolic enzymes. A bioinformatic analysis indicated a STAT3 binding site in the upstream region of SHMT2 gene. We demonstrated that in LNCaP, PCa cells’ SHMT2 expression is upregulated by the JAK2/STAT3 canonical pathway upon IL-6 stimulation. Activation of SHTM2 leads to a decrease in serine levels, pushing PKM2 towards the nuclear compartment where it can activate STAT3 in a non-canonical fashion that in turn promotes a transient shift toward anaerobic metabolism. These results were also confirmed on FFPE prostate tissue sections at different Gleason scores. STAT3/SHMT2/PKM2 loop in LNCaP cells can modulate a metabolic shift in response to inflammation at early stages of cancer progression, whereas a non-canonical STAT3 activation involving the STAT3/HIF-1α/PKM2 loop is responsible for the maintenance of Warburg effect distinctive of more aggressive PCa cells. Chronic inflammation might thus prime the transition of PCa cells towards more advanced stages, and SHMT2 could represent a missing factor to further understand the molecular mechanisms responsible for the transition of prostate cancer towards a more aggressive phenotype.

Factors that drive the increasing use of FFPE tissue in basic and translational cancer research

The decision to use 10% neutral buffered formalin fixed, paraffin embedded (FFPE) archival pathology material may be dictated by the cancer research question or analytical technique, or may be governed by national ethical, legal and social implications (ELSI), biobank, and sample availability and access policy. Biobanked samples of common tumors are likely to be available, but not all samples will be annotated with treatment and outcomes data and this may limit their application. Tumors that are rare or very small exist mostly in FFPE pathology archives. Pathology departments worldwide contain millions of FFPE archival samples, but there are challenges to availability. Pathology departments lack resources for retrieving materials for research or for having pathologists select precise areas in paraffin blocks, a critical quality control step. When samples must be sourced from several pathology departments, different fixation and tissue processing approaches create variability in quality. Researchers must decide what sample quality and quality tolerance fit their specific purpose and whether sample enrichment is required. Recent publications report variable success with techniques modified to examine all common species of molecular targets in FFPE samples. Rigorous quality management may be particularly important in sample preparation for next generation sequencing and for optimizing the quality of extracted proteins for proteomics studies. Unpredictable failures, including unpublished ones, likely are related to pre-analytical factors, unstable molecular targets, biological and clinical sampling factors associated with specific tissue types or suboptimal quality management of pathology archives. Reproducible results depend on adherence to pre-analytical phase standards for molecular in vitro diagnostic analyses for DNA, RNA and in particular, extracted proteins. With continuing adaptations of techniques for application to FFPE, the potential to acquire much larger numbers of FFPE samples and the greater convenience of using FFPE in assays for precision medicine, the choice of material in the future will become increasingly biased toward FFPE samples from pathology archives. Recognition that FFPE samples may harbor greater variation in quality than frozen samples for several reasons, including variations in fixation and tissue processing, requires that FFPE results be validated provided a cohort of frozen tissue samples is available.

Residual tissue repositories as a resource for population-based cancer proteomic studies

BACKGROUND

Mass spectrometry-based proteomics has become a powerful tool for the identification and quantification of proteins from a wide variety of biological specimens. To date, the majority of studies utilizing tissue samples have been carried out on prospectively collected fresh frozen or optimal cutting temperature (OCT) embedded specimens. However, such specimens are often difficult to obtain, in limited in supply, and clinical information and outcomes on patients are inherently delayed as compared to banked samples. Annotated formalin fixed, paraffin embedded (FFPE) tumor tissue specimens are available for research use from a variety of tissue banks, such as from the surveillance, epidemiology and end results (SEER) registries' residual tissue repositories. Given the wealth of outcomes information associated with such samples, the reuse of archived FFPE blocks for deep proteomic characterization with mass spectrometry technologies would provide a valuable resource for population-based cancer studies. Further, due to the widespread availability of FFPE specimens, validation of specimen integrity opens the possibility for thousands of studies that can be conducted worldwide.

METHODS

To examine the suitability of the SEER repository tissues for proteomic and phosphoproteomic analysis, we analyzed 60 SEER patient samples, with time in storage ranging from 7 to 32 years; 60 samples with expression proteomics and 18 with phosphoproteomics, using isobaric labeling. Linear modeling and gene set enrichment analysis was used to evaluate the impacts of collection site and storage time.

RESULTS

All samples, regardless of age, yielded suitable protein mass after extraction for expression analysis and 18 samples yielded sufficient mass for phosphopeptide analysis. Although peptide, protein, and phosphopeptide identifications were reduced by 50, 20 and 76% respectively, from comparable OCT specimens, we found no statistically significant differences in protein quantitation correlating with collection site or specimen age. GSEA analysis of GO-term level measurements of protein abundance differences between FFPE and OCT embedded specimens suggest that the formalin fixation process may alter representation of protein categories in the resulting dataset.

CONCLUSIONS

These studies demonstrate that residual FFPE tissue specimens, of varying age and collection site, are a promising source of protein for proteomic investigations if paired with rigorously verified mass spectrometry workflows.

β-2-himachalen-6-ol protects against skin cancer development in vitro and in vivo

Background

Previous studies in our laboratory showed that Daucus carota oil extract (DCOE) possesses remarkable in-vitro anticancer activity and antitumour promoting effect against DMBA/TPA skin carcinogenesis in mice. Chemical analysis of DCOE led to the isolation of the β-2-himachalen-6-ol (HC), major sesquiterpene with a potent anticancer activity against various colon, breast, brain and skin cancer cells. This study investigated the anticancer activity of HC against invasive epidermal squamous cell carcinoma cells and evaluated its effect in a DMBA/TPA skin carcinogenesis Balb/c murine model.

Methods

HaCaT-ras II-4 epidermal squamous cells were treated with HC (1, 5, 10, 25 and 50 μg/ml), and cell viability was evaluated with WST 1 assay kit. Cell cycle analysis was carried out by flow cytometry, and pro/anti-apoptotic proteins were measured using Western blot. The effect of topical and intraperitoneal (IP) treatment with HC in mice was assessed using the DMBA/TPA skin carcinogenesis model. Cisplatin (2.5 mg/kg; IP) was used as a positive control. Papilloma incidence, yield and volume were monitored, and isolated papillomas were assessed for their pro/anti-apoptotic proteins and morphology.

Results

β-2-himachalen-6-ol showed a dose-dependent decrease in cell survival with an IC50 and IC90 of 8 and 30 μg/ml, respectively. Flow cytometry analysis revealed that treatment with 10 μg/ml HC significantly increased the number of cells undergoing late apoptosis (28%), while 25 μg/ml caused a larger cell shift towards late apoptosis (46.6%) and necrosis (39%). A significant decrease in protein levels of p53 and Bcl-2 and a significant increase in p21 and Bax were observed. Also, there was a significant decrease in p-Erk and p-Akt protein levels. The treatment of mice (IP and topical) with HC caused a significant decrease in papilloma yield, incidence and volume. Similar effects were observed with cisplatin treatment, but HC-treated groups exhibited twofold to threefold increase in survival rates. Similar patterns in the pro- and anti-apoptotic proteins were observed in mice treated with HC, except for a significant increase in p53 protein.

Conclusions

In conclusion, HC treatment induced cell cycle arrest (low dose) and promoted apoptosis partly via inhibition of the MAPK/ERK and PI3K/AKT pathways with no significant toxicity to laboratory mice.

Abnormal alterations of miR-1 and miR-214 are associated with clinicopathological features and prognosis of patients with PDAC

Pancreatic ductal adenocarcinoma (PDAC) is a devastating malignant disease with a poor prognosis. PDAC is known to be difficult to diagnose at an early stage and to exhibit poor recurrence-free prognosis, but there is also a lack of effective treatment and limited knowledge of its biological characteristics. Therefore, there is an urgent requirement for an improved understanding of the cellular or molecular properties associated with PDAC, and to explore novel avenues for the diagnosis and treatment of this disease. In the present study, the microRNA (miRNA/miR) profiles of sera and tumor samples from patients with PDAC and healthy controls were investigated by miRNA microarray, and the potential role of miR-1 expression in PDAC was determined. A total of 43 patients attending the clinic diagnosed with PDAC at Changzhi City People's Hospital were invited to participate. Blood and surgical tumor samples were obtained for analysis by miRNA microarray and the reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The surgical tumor tissue was additionally used to determine miRNAs status by in situ hybridization (ISH). The results of microarray revealed that: i) 27 miRNAs in the sera and 23 miRNAs in the tumor tissues obtained from patients with PDAC were different compared with their matched controls; ii) miR-1, miR-10b and miR-214 were significantly altered in the PDAC group, either in the sera or tumor tissue samples. Results from the RT-qPCR, which detected the levels of miRNAs in patients with PDAC, confirmed those obtained from the miRNA microarray. In particular, the results of the present study revealed that decreased miR-1 and increased miR-214 in the PDAC tissues were associated with the clinicopathological features and survival rates of patients with PDAC. The results of the present study indicated that miRNAs serve an important role in PDAC carcinogenic progression and supplied useful markers, including miR-1, miR-214 and miR-10b, for determining PDAC prognosis using noninvasive methods.

Deparaffinization of formalin-fixed paraffin-embedded tissue blocks using hot water instead of xylene

This study aimed to deparaffinize formalin-fixed paraffin-embedded (FFPE) tissues using hot water instead of xylene and measuring the quantity and quality of the extracted DNA from the respective tissues. To deparaffinize the tissue sections with hot water, small sections were exposed to 90 °C distilled sterile water. After 25 FFPE tissue samples were deparaffinized with the hot water method, DNA was then extracted. The mean of optical density and the ratio of absorbance of the DNA solution were 220.01 ± 36.1 ng/μl and 1.65 ± 0.1, respectively. Polymerase chain reaction (PCR) analysis of the toll-like receptor 4(TLR4) gene showed that the method can be used as a tool for different applications.