A Highly Sensitive and Rapid Colloidal Gold Immunoassay for Puerarin Detection.

Radix Puerariae is a traditional Chinese medicinal material with a rich history of use in East and Southeast Asia. Puerarin, a unique component of the Pueraria genus, serves as a quality control marker for herbal medicines like Pueraria lobata and Pueraria thomsonii in China, displaying diverse pharmacological properties. This study developed puerarin colloidal gold immunoassay dipsticks utilizing an anti-puerarin monoclonal antibody, resulting in a fast and sensitive detection method with a limit of 500-1000 ng·mL-1. Evaluation using tap water-extracted P. lobata and P. thomsonii samples showed consistent results compared to LC-MS analysis. Cross-reactivity assessments of puerarin analogs revealed minimal interference, affirming the dipstick's reliability for distinguishing between the two species.

Click Reaction-Mediated Fluorescent Immunosensor Based on Cu-MOF Nanoparticles for Ultrasensitive and High-Throughput Detection of Aflatoxin B1 in Food Samples.

Due to the high toxicity of aflatoxin B1 and its risks to human health, we developed a click reaction-mediated automated fluorescent immunosensor (CAFI) for sensitive detection of aflatoxin B1 based on the Cu(I)-catalyzed click reaction. With its large specific surface area, a copper-based metal-organic framework (Cu-MOF) was synthesized to adsorb and enrich the copper ion (Cu(II)) and then load the complete antigen (BSA-AFB1). After the immunoreaction, Cu(II) inside the Cu-MOF-Antigen conjugate would be reduced to Cu(I) in the presence of sodium ascorbate, which triggered the click reaction between the fluorescent donor-modified DNA and the receptor-modified complementary DNA to lead to a fluorescence signal readout. The whole reaction steps were finished by the self-developed automated immunoreaction device. This CAFI method showed a limit of detection (LOD) of 0.48 pg/mL as well as a 670-fold enhancement in sensitivity compared to conventional ELISA, revealing its great potential in practical applications and automated detection.

Simultaneous rapid detection of glycyrrhizin and sennoside A in Daiokanzoto samples by lateral flow immunoassay.

INTRODUCTION: Glycyrrhizin (GLY) and sennoside A (SA) are characteristic bioactive marker compounds of the Kampo medicine Daiokanzoto. Their accurate detection in blends of Rhei rhizoma and Glycyrrhizae radix of several species (4:1 or 4:2) is essential for quality control and to ensure therapeutic efficacy. A rapid, efficient assay can significantly facilitate their detection. OBJECTIVE: To establish a rapid qualitative assay for GLY and SA detection, a lateral flow immunoassay (LFA) was developed using specific monoclonal antibody (mAb) nanoparticles. METHODOLOGY: This assay harnesses the competitive binding of mAb nanoparticles to the immobilized analytes on test strips and free analytes in the samples. Two conjugates for detecting GLY and SA, GLY-bovine serum albumin and SA-human serum albumin, were separately immobilized on the test zones of LFA strips. The detection mechanism is reliant on the visual detection of color changes in the test zones. RESULTS: When GLY and SA were present in samples, they contended with the immobilized conjugates on the strip to bind with the mAb nanoparticles and produced distinct color patterns in the test zones. The limits of detection of the assay for GLY and SA were both 3.13 µg/mL. The capability of the LFA was substantiated using plant samples and Daiokanzoto, and its alignment with indirect competitive ELISA results was confirmed. CONCLUSION: The introduced LFA is a groundbreaking procedure that offers a rapid, straightforward, and sensitive method for simultaneously detecting GLY and SA in Daiokanzoto samples. It is instrumental in ensuring product quality.

Interference against a newly labeled substance with ruthenium sulfonate complexes showing discrepant thyroid function test results.

We report here two patients exhibiting a combination of falsely elevated serum levels of free thyroxine (FT4), free triiodothyronine (FT3), and thyrotropin receptor antibodies (TRAb), measured using Elecsys assay kits (Roche Diagnostics GmbH). The first patient was a 74-year-old man misdiagnosed with Graves' disease and treated with methimazole. The second patient was a 48-year-old woman whose serum FT4 and FT3 concentrations were found to be high during a blood test. These patients denied taking biotin or any other supplements. Further detailed examination, including a heterophilic blocking tube test, revealed the presence of serum antibodies. The abnormal reactions were observed only using the improved assay kits using ruthenium (Ru) sulfonate instead of Ru as a chemiluminescent agent. Therefore, serum antibodies to the Ru sulfonate complex caused the pseudo-high levels of FT4, FT3, and TRAb. To our knowledge, this is the first report showing that antibodies to the Ru sulfonate complex in the electrochemiluminescence immunoassay can cause falsely elevated levels of the combination, leading to discrepant thyroid function test results. We emphasize that in cases of abnormal test results, alternative assay methods should be considered for further examination; unusual test results should not be impulsively interpreted, even when using revised assay kits.

Generating Monoclonal Antibodies against Buprofezin and Developing Immunoassays for Its Residue Detection in Tea Samples.

The synthesis of a hapten and antigen for the preparation of a monoclonal antibody (mAb) for buprofezin is described. The recognition mechanism of hapten and buprofezin by monoclonal antibodies (mAb-19F2) is described. The effectiveness of the mAb-19F2 immunoassay technique was assessed, and the effective detection of buprofezin in tea samples was achieved through the establishment of indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and colloidal gold immunochromatography assay (GICA). The mAb-19F2 subtype was IgG1, with an IC50 of 1.8 ng/mL and a linear range (IC20-IC80) of 0.6-5.4 µg/L, and had a cross-reaction rate of less than 0.18% with 29 other pesticides (neonicotinoids and insect growth regulators). The study identified π-π stacking interactions between hapten and TYR-61 at the mAb-19F2 site and alkyl/phosphate interactions with TRP-105 and ARG-103. The ic-ELISA had an IC50 of 12.9 ng/mL in green tea and 5.65 ng/mL in black tea, with a recovery rate of 92.4%-101.0% and RSD of 2.1%-4.8%. The GICA had a limit of detection (LOD) was 500 ng/mL, with the complete disappearance of the test lines visible to the naked eye. The limit of quantitation (LOQ, IC20) was determined to be 16.8 ng/mL. Additionally, the developed GICA showed no cross-reactivity with neonicotinoid pesticides. The recovery rate of tea spiked recovered samples was 83.6%-92.2%, with an RSD of 5.3%-12.6%, and the results were consistent with the LC/MS method. This study is important for the real-time detection of buprofezin residues to ensure food safety and human health.

Determination of vitamin D status in singleton and twin gestations using CLIA and LC-MS/MS.

Objective: Vitamin D plays an important role during pregnancy. The aim was to compare vitamin D status in a group of singleton (SP) and twin pregnancies (TP) using two diagnostic methods: chemiluminescence immunoassay (CLIA) and liquid chromatography with tandem mass spectrometry (LC-MS/MS). Design: This is a cross-sectional study. Methods: The study was conducted in the population of SP and TP at the gestational age above 20 + 0 at the Bielanski Hospital in Warsaw, Poland, between October 2020 and January 2023. All patients had their venous blood samples collected and were given an original survey containing questions on demography and vitamin D supplementation. Results: The study group included 53 Caucasian women with SP and 78 with TP aged from 21 to 47. Considering LC-MS/MS, patients with TP had lower concentrations of 25-hydroxyvitamin D (25(OH)D) than patients with SP. However, no significant difference was observed in the frequency of the occurrence of vitamin D deficiency (25(OH)D < 30 ng/mL). In both groups, the levels obtained with CLIA were significantly lower than in case of LC-MS/MS, however, strongly correlated. The intermethod agreement accounted for 52.4% and the Cohen's kappa coefficient was 0.142. Conclusions: The concentration of 25(OH)D in pregnant women depends on the type of gestation (SP/TP) and on the diagnostic methods used (CLIA/LC-MS/MS). Based on LC-MS/MS, the incidence of vitamin D deficiency was low in our group and no differences occurred in its frequency between SP and TP. The intermethod agreement between CLIA and LC-MS/MS on the detection of vitamin D deficiency was low. Significance statement: This is the first study to compare the concentration of 25(OH)D levels between SP and TP using two methods: CLIA and the gold standard - LC-MS/MS. Based on LC-MS/MS, a low incidence of vitamin D deficiency was observed in our group, in which the vast majority of patients took cholecalciferol supplements. Moreover, there were no differences in its frequency between SP and TP. However, the 25(OH)D level was significantly lower in TP. The intermethod agreement between CLIA and LC-MS/MS on the detection of vitamin D deficiency was low, which is associated with substantial clinical implications.

Lack of Consensus Between Measurements of Plasma Phylloquinone by Enzyme-Linked Immunosorbent assays and a Well-Validated High-Performance Liquid Chromatographic Method.

Enzyme-linked i2mmunosorbent assays (ELISAs) that measure circulating phylloquinone have become commercially available, but their validity is uncertain. The objective of this study was to compare plasma phylloquinone concentrations measured using two commercially available ELISAs with concentrations measured using a validated high-performance liquid chromatography (HPLC) assay in 108 samples obtained from participants in a depletion (∼10 mcg phylloquinone/d)-supplementation (∼500 mcg phylloquinone/d) study. The geometric mean of plasma phylloquinone measured with ELISA A was 0.70 nmol/L, 37% lower than that measured with HPLC. The mean of the ELISA B measures was 12.4 nmol/L, >700% higher than the HPLC measures. Plasma phylloquinone measured using HPLC was significantly lower during phylloquinone depletion than supplementation (0.4 ± 0.1 compared with 1.2 ± 0.2 nmol/L; P < 0.001). Neither of the two ELISAs detected any significant difference in plasma phylloquinone concentrations between depletion and supplementation (ELISA A, P = 0.76; ELISA B, P = 0.29). These findings reinforce the need to validate plasma phylloquinone assays as they become available. Curr Dev Nutr 2023;x:xx.

Biotin induced biochemical hyperthyroidism: a case report and review of the literature.

BACKGROUND: Biotin is a commonly used supplement for hair, nail, and skin. Recent literature suggests that high-dose biotin therapy for neurological diseases like Multiple sclerosis can interfere with lab results that use biotin/streptavidin immunoassay, called biotin interference. Biotin interference can affect thyroid lab results, giving biochemical hyperthyroidism. CASE PRESENTATION: Our patient, a 64-year-old white man with a known history of multiple sclerosis, presented with elevated free T3, free T4, and low TSH that resembled hyperthyroidism. He had no symptoms of hyperthyroidism except some fatigue and tachycardia on the first encounter. He was started on anti-thyroid medications. He was then re-evaluated since his lab results remained the same after two months of anti-thyroid medications. It was found that he was on biotin, 10000mcg/day, for his multiple sclerosis. Biotin was discontinued, and five days later his lab results returned to normal values. CONCLUSION: The lack of knowledge of biotin use by patients can lead to misdiagnosis of patients' thyroid lab results and improper management. Awareness about biotin interference and abnormal thyroid lab values should be a priority among clinicians and the public. If the biotin is discontinued on time, such misdiagnosis can be avoided.

Elevated free thyroxine and free triiodothyronine probably caused by high-dose biotin intake in a patient with Graves' disease: a case report.

Biotin is a water-soluble vitamin that acts as a cofactor for carboxylase, and is often used as a component in several immunoassays. We present a case of a 46-year-old male with Graves' disease (GD) who revealed elevated free thyroxine (FT4) and free triiodothyronine (FT3) levels after high-dose biotin intake. Levels of these hormones had been within the reference range when he was on thiamazole 5 mg/day for 7 years; however, the levels increased from 1.04 to 2.20 ng/dL and from 3.05 to 9.84 pg/mL for FT4 and FT3, respectively, after he started taking biotin 72 mg/day. Despite these high levels, his symptoms and the other laboratory results, including the thyroid-stimulating hormone level, did not suggest GD relapse. His thyroid hormone data was decreased and returned within the reference range immediately after the laboratory assays for FT3 and FT4 had been coincidentally changed from those containing streptavidin-biotin complexes to biotin-free ones. Biotin interference, which is caused by high-dose biotin intake and immunoassays using some form of streptavidin-biotin complex, is sometimes clinically problematic, giving high or low results. To our knowledge, this is the first case report of a patient with GD on high-dose biotin receiving high thyroid hormone level results that were initially misunderstood as an aggravation of the disease; there are some reports of misdiagnosis of hyperthyroidism due to biotin administration. Unexpected fluctuations in thyroid function test results in patients with GD should be checked for biotin intake, immunoassays and the limiting concentration of biotin to avoid misdiagnosis of relapse.

Decreased Immunoreactivity of Hepatitis E Virus Antigen Following Treatment with Sakhalin Spruce (Picea glehnii) Essential Oil.

The hepatitis E virus (HEV) causes a common infectious disease that infects pigs, wild boars, deer, and humans. In most cases, humans are infected by eating raw meat. Some essential oils have been reported to exhibit antiviral activities. In this study, in order to investigate the anti-HEV properties of essential oils, the immunoreactivities of HEV antigen proteins against the relevant antibodies were analyzed after the HEV antigens underwent treatment with various essential oils. The essential oils extracted from the tea tree, which was previously reported to exhibit antiviral activity, lavender, and lemon had strongly reduced activity. We found that treatment with the essential oil prepared from Sakhalin spruce was associated with the strongest reduction in immunoreactivity of HEV antigen protein(s) among the tested substances. The main volatile constituents of Sakhalin spruce essential oil were found to be bornyl acetate (32.30 %), α-pinene (16.66 %), camphene (11.14 %), camphor (5.52 %), ß-phellandrene (9.09 %), borneol (4.77 %), and limonene (4.57 %). The anti-HEV properties of the various components of the essential oils were examined: treatment with bornyl acetate, the main component of Sakhalin spruce oil, α-pinene, the main component of tea tree oil, and limonene, the main component of lemon oil, resulted in a strong reduction in HEV antigen immunoreactivity. These results indicate that each main component of the essential oils plays an important role in the reduction of the immunoreactivity of HEV antigen protein(s); they also suggest that Sakhalin spruce essential oil exhibits anti-HEV activity. In a formulation with the potential to eliminate the infectivity of HEV in foodborne infections, this essential oil can be applied as an inactivating agent for meat processing and cooking utensils, such as knives and chopping boards.

Challenges in the diagnosis of hypervitaminemia B12. Interference by immunocomplexes.

BACKGROUND-AIM: High vitamin B12 concentrations are considered a common finding in clinical practice. Thanks to immunoassay accessibility, vitamin B12 has become a usual test in routine health checkups. However, these analytical methods usually present antibody-mediated interferences. Our aim was to propose an algorithm for the screening of antibody-mediated analytical interferences on vitamin B12 immunoassays on the Alinity platform. METHODS: Observational, prospective, case-control study was performed during 12 months. Individuals with persistently elevated cobalamin concentrations [>554 pmol/L] were considered as cases in the absence of supplementation or other justifying cause. Individuals under treatment with vitamin B12, or in the context of alcoholism were included as controls. A thorough interference study by macromolecules in immunoassays was performed in serum samples: PEG precipitation, rheumatoid factor, heterophile antibodies and gel permeation chromatography (GPC). Albumin, total B12, IgG and IgM were measured in every GPC collected fraction and chromatograms were drafted. RESULTS: Up to 45% of cases presented interference by B12-immunocomplexes and the precipitation for all of them was >50%. The individual with the lowest interfered vitamin B12 result was 661 pmol/L. CONCLUSION: The presence of antibody-mediated interferences, mainly B12-immunocomplexes, is a relatively common phenomenon. A simple algorithm for the screening of interferences is useful and reliable in ruling out healthy individuals and highly cost-effective.

Assessing vitamin D metabolism - four decades of experience.

One hundred years ago, the role of vitamin D for bone mineralization and the prevention of rickets was discovered. Vitamin D comprises a group of over 50 metabolites with multiple functions that go far beyond calcium homeostasis and bone mineralization. Approximately 50 years ago, first methods for the measurement of 25-hydroxyvitamin D (25(OH)D) in human blood were developed. Over the years, different analytical principals were employed including competitive protein binding assays, high-performance liquid chromatography, various immunoassay and mass spectrometric formats. Until the recent standardization of serum 25(OH)D measurement, agreement between methods was unsatisfactory. Since then, comparability has improved, but substantial variability between methods remains. With the advent of liquid chromatography tandem mass spectrometry (LC-MS/MS), the accurate determination of 25(OH)D and other metabolites, such as 24,25(OH)2D, becomes increasingly accessible for clinical laboratories. Easy access to 25(OH)D testing has triggered extensive clinical research showing that large parts of the population are vitamin D deficient. The variable response of vitamin D deficient individuals to supplementation indicates that assessing patients' vitamin D stores by measuring 25(OH)D provides limited insight into the metabolic situation. Meanwhile, first evidence has emerged suggesting that the simultaneous measurement of 25(OH)D, 24,25(OH)2D and other metabolites allows a dynamic evaluation of patients' vitamin D status on metabolic principals. This may help to identify patients with functional vitamin D deficiency from those without. It can be expected that research into the assessment vitamin D status will continue for another 50 years and that this will help rationalizing our approach in clinical practice.

Chemiluminescence Immunoassay Method of Urinary Liver Fatty-acid-binding Protein as a Promising Candidate for Kidney Disease.

Liver fatty acid binding protein (L-FABP) is an intercellular lipid chaperone protein that selectively combines with unsaturated free fatty acids and transports them to mitochondria or peroxisomes. L-FABP is a promising biomarker for the early detection of renal diseases in humans. Herein a chemiluminescence method (CLIA) was demonstrated to measure the level of urinary L-FABP in the urinary samples. An anti-(L-FABP)-magnetic beads complex was prepared to capture the analyte target. Sensitivity, precision, accuracy, interference effect, high-dose hook effect of the developed assay were evaluated. Under the suitable experimental parameters, the established method have a wide linear range (0.01-10 ng/mL) and also showed a sufficiently low limit of detection of 0.0060 ng/mL. Besides, the satisfactory recoveries of the method in the urinary were ranged from 97.74%-112.32%, which was well within the requirement of clinical analysis. Furthermore, this proposed method has been successfully applied to the clinical determination of L-FABP in patients who have been diagnosed with kidney disease. The results showed that CLIA could accurately and rapidly determine the urinary level of L-FABP with high-throughput, which could be useful as a new tool to predict complications in patients with kidney disease. The clinical trial was approved by Shuyang Hospital of Traditional Chinese Medicine Ethics Committee: 20,210,202-001 at February 2, 2021.

Development of an automated chemiluminescent immunoassay for cancer antigen 72-4 and the evaluation of its analytical performance.

Objectives: Cancer antigen (CA) 72-4 assay is widely used for monitoring gastric and ovarian cancers. The antigen is a mucin-like, tumor-associated glycoprotein known as TAG-72. It has been identified and characterized using two different monoclonal antibodies, CC49 and B72.3, which recognize its glycochain epitopes, Galß(1-3) sialyl-Tn and sialyl-Tn antigens, respectively. This study describes the quantitative analytical performance of a newly developed CA 72-4 assay, ARCHITECT CA 72-4. Design: and Methods: The ARCHITECT CA 72-4 assay was developed using the ARCHITECT i2000SRs and three ARCHITECT i1000SRs. The assay performance was evaluated based on guidance from CLSI (Clinical and Laboratory Standards Institute) and correlation against Elecsys CA 72-4. Results: In the total precision study, the minimum coefficient of variation (CV) for Control/Panel samples over 4 U/mL was 1.1%. The measuring interval was from 0.95 to 200 U/mL with good linearity; and limits of blank (LoB), detection (LoD), and quantitation (LoQ) were 0.09, 0.18, and 0.95 U/mL, respectively. High dose hook effect; differences among specimen tube types; and interference of common drugs, potential cross-reactants, and endogenous substances were not observed. Significantly, this assay has high biotin tolerance at 4875 mg/mL and correlates well with the Elecys CA 72-4 assay (correlation coefficient: 0.95). Conclusions: ARCHITECT CA 72-4 is a highly sensitive and precise assay for CA 72-4 measurement in human sera and plasma.

An ultra-sensitive photothermal lateral flow immunoassay for 17ß-estradiol in food samples.

Hormone residues in food and drinking water endanger human health, therefore, on-site analysis techniques of superior performance are important for monitoring this risk. In this study, an ultra-sensitive photothermal lateral flow immunoassay (LFIA) for quantification of 17ß-estradiol (E2) has been developed. Anti-E2 antibody modified black phosphorus-Au (BP-Au) nanocomposite was developed as a photothermal contrast signal probe and the temperature at test-zone was recorded with an infrared camera. Under the irradiation of 808 nm laser at test-zone, it gave temperatures negatively related to the concentrations of E2 in samples. Under optimal detecting conditions, the developed photothermal LFIA exhibited a limit of detection of 50 pg mL-1, over 100-fold more sensitive than visual LFIA, and a linear range of 3 orders of magnitude. This method has been successfully applied to water, milk, and milk powder samples.

Development of a photothermal-sensing microfluidic paper-based analytical chip (PT-Chip) for sensitive quantification of diethylstilbestrol.

The continuous intake of diethylstilbestrol (DES) residue seriously threatens the health of consumers, so the rapid and sensitive detection of DES is helpful for timely food safety warning. In this study, a photothermal-sensing microfluidic paper-based analytical chip (PT-Chip) was developed for effectively screening of DES residue in foods. Competitive inhibition immunochromatography was introduced and the composite of black phosphorus nanosheets and gold nanoparticles (BP-Au) was used as signal indicators. Then, the test area was irradiated by an 808 nm laser and the photothermal transduction signal was recorded by a thermal imager to achieve sensitive photothermal detection. The amount of DES was obtained by analyzing the temperature change curve of test area. The PT-Chip can achieve accurate quantification of DES with a detection limit of 0.1 µg/L. And the successful determination of DES in different food samples indicating that the PT-Chip can be used as a promising detection device.

Melatonin as an Antimicrobial Adjuvant and Anti-Inflammatory for the Management of Recurrent Clostridioides difficile Infection.

Background:Clostridioides difficile (C. difficile) infection (CDI) is strongly associated with inflammation and has the potential to cause recurrent infections. Pre-clinical data suggest that melatonin has beneficial effects in the gastrointestinal tract due to its anti-inflammatory and antibacterial properties. This analysis examines the association between melatonin and the risk of recurrent CDI. Methods: A retrospective cohort study was conducted among patients with an inpatient diagnosis of CDI along with a positive C. difficile polymerase chain reaction (PCR) or enzyme immunoassay (EIA) test result. Patients were followed until the first study end point (death) or the first instance of recurrent infection. Propensity-score weighting was utilized accounting for confounding factors and weighted Cox models were estimated. Results: A total of 24,782 patients met the inclusion criteria, consisting of 3457 patients exposed to melatonin and 21,325 patients with no melatonin exposure. The results demonstrate that those exposed to melatonin were associated with a 21.6% lower risk of recurrent CDI compared to patients without melatonin exposure (HR = 0.784; 95% CI = 0.674-0.912). Conclusion: Our results demonstrate a decreased rate of recurrent CDI in patients exposed to melatonin. Further research on melatonin as an antimicrobial adjuvant and anti-inflammatory is warranted for the management of recurrent CDI.

Development of Highly Sensitive Chemiluminescence Enzyme Immunostaining Assay to Determine Glycyrrhizin Content Using Anti-glycyrrhizin Monoclonal Antibody.

Licorice, the root of Glycyrrhiza spp., is used in a large number of herbal medicines, such as traditional Chinese medicines, Japanese Kampo medicines, and therapeutic drugs. Since glycyrrhizin (GL) is among the main components in licorice and exhibits numerous beneficial pharmacological activities, the content of GL directly affects biological activity. The quality control based on GL content is an important factor in ensuring biological activity; however, the content of GL in licorice varies depending on plant cultivation environment, genetic factors, and species type. Previously, we prepared an anti-GL monoclonal antibody (anti-GL mAb) and employed it in various immunochemical assays for quality control of licorice and licorice-based products. In this study, we employed the anti-GL mAb in chemiluminescence enzyme immunostaining (CLEIS) to develop a very simple, rapid, specific, and sensitive quality control assay for licorice products, with a limit of detection of 3.9 ng. Furthermore, the CLEIS assay enabled semiquantitative analysis of GL in Kampo medicines. Our results showed that multiple samples can be simultaneously analyzed using CLEIS, and it is a useful tool for determining GL content, as well as ensuring chemical quality control of licorice-containing products and herbal medicines.

Correlation between 25-hydroxy vitamin D levels in women and in vitro fertilization outcomes: A cross-sectional study.

Background: Vitamin D has recently raised a great deal of controversy, not because of its traditional role of absorbing calcium and maintaining bone health, but because of its unconventional role as an endocrine factor and the extent of its impact when linked to its specific receptors (VDR) found in different tissues. Research has raced trying to find its different roles in those tissues and its association with different clinical or medical conditions, and among these cases, its role in reproductive functions and fertility in women, these studies conflicted between supporting and denying the role of vitamin D in reproductive function and rejecting this hypothesis according to the results of their study. Materials and methods: The in vitro fertilization process allowed us to study the possible hypotheses, as this technique provides an opportunity to study the relationship between vitamin D levels with the in vitro fertilization outcomes, thus providing us with an idea of the relationship of vitamin D with fertility in women. In order to study this relationship, we designed our research as a cross-sectional study to confirm or deny this claim. Vitamin D was measured in the blood and in the follicular fluid for all cases using the electrochemiluminescence immunoassay (ECLIA) for the assay of total vitamin D, then IVF outcomes were compared with the levels of vitamin D in the blood. Results: the levels of vitamin D are not related to the criteria of eggs such as the number of eggs and the maturity rate (MR) of eggs, but they are correlated in a statistically significant manner with the fertility rate (FR), and at the same time the levels of vitamin D in the blood were completely independent of the clinical pregnancy rate (CPR). Conclusion: blood vitamin D levels will affect the FR when its levels in the blood drop below a specified value, vitamin D did not correlate with the CPR. In the long run, there is scope for more research projects on vitamin D. Future research could include case-control studies of patients on vitamin D supplementation, and the study of its correlation with IVF outcomes.

AuNPs-based lateral flow immunoassay for point-of-needs analysis of four neonicotinoids in tea samples: Effects of grinding degrees, solvent types and contents on extraction efficiency.

The higher extraction efficiency of analytes is crucial for developing immunoassays with high accuracy. Here, we evaluated the extraction efficiency of neonicotinoids in tea samples in terms of grinding degrees, extraction solvents types and contents. Fragments for fresh tea leaves (1 g, 5-10 mm2) or tea powder (1 g, 35 mesh) for commercial tea was extracted with 100 % methanol. The extraction (1 mL) was diluted 10-fold with buffer solution, and then submitted to gold nanoparticles-based lateral flow immunoassay. This optimal extraction protocol exhibited a higher extraction efficiency (72.4-99.3 %) for the positive neonicotinoids samples. The cut-off values of lateral flow immunoassay were 0.325 or 0.65 µg/g, 0.3 or 0.45 µg/g, 0.3 or 0.45 µg/g, 0.03 or 0.06 µg/g for thiamethoxami, clothianidin, acetamiprid and midacloprid in fresh tea leaves and commercial tea. In summary, this proposed lateral flow immunoassay can be used as the point-of-needs analysis method for four neonicotinoids in tea.