Biomedical subjects

Yang Wu

Publications and source records attributed to Yang Wu.

At least 19 recordsLinked to original sources

PubMed2025

Mendel randomization confirmed gastroesophageal reflux disease may increase the risk of mental disorders.

BACKGROUND: The potential causal relationship between gastroesophageal reflux disease (GERD) and mental disorder was analyzed using the mendelian randomization (MR) method. METHODS: Data are derived from genome-wide association study (GWAS) summary data, using gastroesophageal reflux disease (GERD) as the exposure factor. Single nucleotide polymorphisms (SNPs) significantly associated with GERD were selected as instrumental variables (IVs), and mental disorders (bipolar disorder, major depression, Alzheimer's disease, anorexia nervosa, anxiety, and obsessive-compulsive disorder) were used as outcome variables. The inverse variance weighted (IVW) method is used as the main analysis method, and MR-Egger regression, weighted median (WM) method, simple mode and weighted mode are used as supplementary methods for Mendelian randomization (MR) analysis. Cochran's Q test and P value are used to quantify heterogeneity, MR-Egger regression was used to evaluate the multilevel effect test of SNPs, and leave-one-out method to determine whether there are potential SNPs, and to evaluate the stability of the results. Odds ratio (OR) and 95% confidence interval (CI) were used as effect indicators to evaluate whether there is a causal relationship between GERD and mental disorders. RESULTS: IVW demonstrated a causal relationship between GERD and bipolar disorder (OR = 1.70, 95%CI = 1.39-2.09, P < 0.05) and anorexia nervosa (OR = 0.71, 95%CI = 0.52-0.99, P < 0.05). Furthermore, there is a weak causal relationship between GERD and major depression (OR = 1.01, 95%CI = 1.01-1.02, P < 0.05) and anxiety (OR = 1.01, 95%CI = 1.01-1.01, P < 0.05). Similarly, there is no evidence of a causal relationship between GERD and Alzheimer's disease (OR = 0.95, 95%CI = 0.87-1.03, P > 0.05) or obsessive-compulsive disorder (OR = 0.95, 95%CI = 0.67-1.36, P > 0.05). Cochran's Q test for heterogeneity shows that there is no significant heterogeneity (P > 0.05) for bipolar disorder, anxiety, and obsessive-compulsive disorder. However, major depression, Alzheimer's disease, and anorexia nervosa have some degree of heterogeneity (P < 0.05). Horizontal pleiotropic analysis showed that the P values for six mental disorders (0.750, 0.296, 0.154, 0.798, 0.893, 0.451) were all greater than 0.05. Leave-one-out analysis and funnel plot showed that MR analysis results can be considered relatively stable. All F are > 10, indicating no weak IVs bias. CONCLUSION: GERD can obviously increase the risk of bipolar disorder; the increased risk of anxiety disorder is very slight. There is no clear evidence to support the causal relationship between GERD and four other mental disorders, including major depression, Alzheimer's disease, anorexia nervosa, and obsessive-compulsive disorder.

Humans↗

PubMed2025

Anticancer drug response prediction integrating multi-omics pathway-based difference features and multiple deep learning techniques.

Individualized prediction of cancer drug sensitivity is of vital importance in precision medicine. While numerous predictive methodologies for cancer drug response have been proposed, the precise prediction of an individual patient's response to drug and a thorough understanding of differences in drug responses among individuals continue to pose significant challenges. This study introduced a deep learning model PASO, which integrated transformer encoder, multi-scale convolutional networks and attention mechanisms to predict the sensitivity of cell lines to anticancer drugs, based on the omics data of cell lines and the SMILES representations of drug molecules. First, we use statistical methods to compute the differences in gene expression, gene mutation, and gene copy number variations between within and outside biological pathways, and utilized these pathway difference values as cell line features, combined with the drugs' SMILES chemical structure information as inputs to the model. Then the model integrates various deep learning technologies multi-scale convolutional networks and transformer encoder to extract the properties of drug molecules from different perspectives, while an attention network is devoted to learning complex interactions between the omics features of cell lines and the aforementioned properties of drug molecules. Finally, a multilayer perceptron (MLP) outputs the final predictions of drug response. Our model exhibits higher accuracy in predicting the sensitivity to anticancer drugs comparing with other methods proposed recently. It is found that PARP inhibitors, and Topoisomerase I inhibitors were particularly sensitive to SCLC when analyzing the drug response predictions for lung cancer cell lines. Additionally, the model is capable of highlighting biological pathways related to cancer and accurately capturing critical parts of the drug's chemical structure. We also validated the model's clinical utility using clinical data from The Cancer Genome Atlas. In summary, the PASO model suggests potential as a robust support in individualized cancer treatment. Our methods are implemented in Python and are freely available from GitHub (https://github.com/queryang/PASO).

Deep Learning↗

PubMed2024

Transcriptomic analysis reveals key molecular signatures across recovery phases of hemorrhagic fever with renal syndrome.

BACKGROUND: Hemorrhagic fever with renal syndrome (HFRS), a life-threatening zoonosis caused by hantavirus, poses significant mortality risks and lacks specific treatments. This study aimed to delineate the transcriptomic alterations during the recovery phases of HFRS. METHODS: RNA sequencing was employed to analyze the transcriptomic alterations in peripheral blood mononuclear cells from HFRS patients across the oliguric phase (OP), diuretic phase (DP), and convalescent phase (CP). Twelve differentially expressed genes (DEGs) were validated using quantitative real-time PCR in larger sample sets. RESULTS: Our analysis revealed pronounced transcriptomic differences between DP and OP, with 38 DEGs showing consistent expression changes across all three phases. Notably, immune checkpoint genes like CD83 and NR4A1 demonstrated a monotonic increase, in contrast to a monotonic decrease observed in antiviral and immunomodulatory genes, including IFI27 and RNASE2. Furthermore, this research elucidates a sustained attenuation of immune responses across three phases, alongside an upregulation of pathways related to tissue repair and regeneration. CONCLUSION: Our research reveals the transcriptomic shifts during the recovery phases of HFRS, illuminating key genes and pathways that may serve as biomarkers for disease progression and recovery.

Hemorrhagic Fever with Renal Syndrome↗

PubMed2006

Structure-based discovery of inhibitors of the YycG histidine kinase: new chemical leads to combat Staphylococcus epidermidis infections.

BACKGROUND: Coagulase-negative Staphylococcus epidermidis has become a major frequent cause of infections in relation to the use of implanted medical devices. The pathogenicity of S. epidermidis has been attributed to its capacity to form biofilms on surfaces of medical devices, which greatly increases its resistance to many conventional antibiotics and often results in chronic infection. It has an urgent need to design novel antibiotics against staphylococci infections, especially those can kill cells embedded in biofilm. RESULTS: In this report, a series of novel inhibitors of the histidine kinase (HK) YycG protein of S. epidermidis were discovered first using structure-based virtual screening (SBVS) from a small molecular lead-compound library, followed by experimental validation. Of the 76 candidates derived by SBVS targeting of the homolog model of the YycG HATPase_c domain of S. epidermidis, seven compounds displayed significant activity in inhibiting S. epidermidis growth. Furthermore, five of them displayed bactericidal effects on both planktonic and biofilm cells of S. epidermidis. Except for one, the compounds were found to bind to the YycG protein and to inhibit its auto-phosphorylation in vitro, indicating that they are potential inhibitors of the YycG/YycF two-component system (TCS), which is essential in S. epidermidis. Importantly, all these compounds did not affect the stability of mammalian cells nor hemolytic activities at the concentrations used in our study. CONCLUSION: These novel inhibitors of YycG histidine kinase thus are of potential value as leads for developing new antibiotics against infecting staphylococci. The structure-based virtual screening (SBVS) technology can be widely used in screening potential inhibitors of other bacterial TCSs, since it is more rapid and efficacious than traditional screening technology.

Amino Acid Sequence↗

PubMed2006

[Binding fistulojejunostomy for the treatment of external pancreatic fistula].

OBJECTIVE: To evaluate the safety and feasibility of binding fistulojejunostomy, a new operative procedure, in the treatment of external pancreatic fistula. METHODS: Eight patients suffering from external pancreatic fistula, 4 males and 4 females, aged 49 (22 approximately 69), underwent binding fistulojejunostomy: 2 cm-length of fistula was isolated and a tube was inserted therein, the jejunum was transected and the distant cut end was everted for the length of 3 cm, the mucosa of the everted jejunum was destroyed with carbolic acid, the everted mucosa of jejunum and the fistula were brought together and sutured with silk, the everted jejunum was then turned back to wrap over the fistula, a silk tie was lopped around the entire circumference of the anastomosis, and lastly, the tube was led out of the abdominal wall. RESULTS: all 8 patients recovered smoothly without pancreatic leakage and other complications. CONCLUSION: Binding fistulojejunostomy is safe and effective for the treatment of external pancreatic fistula.

Adult↗

PubMed2006

Comparative proteomic analysis of metabolically labelled proteins from Plasmodium falciparum isolates with different adhesion properties.

The virulence of Plasmodium falciparum relates in part to the cytoadhesion characteristics of parasitized erythrocytes but the molecular basis of the different qualitative and quantitative binding phenotypes is incompletely understood. This paucity of information is due partly to the difficulty in working with membrane proteins, the variant nature of these surface antigens and their relatively low abundance. To address this two-dimensional (2D) protein profiles of closely related, but phenotypically different laboratory strains of P. falciparum have been characterized using proteomic approaches. Since the mature erythrocyte has no nucleus and no protein synthesis capability, metabolic labelling of proteins was used to selectively identify parasite proteins and increase detection sensitivity.A small number of changes (less than 10) were observed between four different P. falciparum laboratory strains with distinctive cytoadherence properties using metabolic labelling, with more parasite protein changes found in trophozoite iRBCs than ring stage. The combination of metabolic labelling and autoradiography can therefore be used to identify parasite protein differences, including quantitative ones, and in some cases to obtain protein identifications by mass spectrometry. The results support the suggestion that the membrane protein profile may be related to cytoadherent properties of the iRBCs. Most changes between parasite variants were differences in iso-electric point indicating differential protein modification rather than the presence or absence of a specific peptide.

Animals↗

PubMed2006

An independent component analysis approach for minimizing effects of recirculation in dynamic susceptibility contrast magnetic resonance imaging.

In dynamic susceptibility contrast (DSC) perfusion-weighted imaging, effects of recirculation are normally minimized by a gamma-variate fitting procedure of the concentration curves before estimating hemodynamic parameters. The success of this method, however, hinges largely on the extent to which magnetic resonance signal is altered in the presence of a contrast agent and a temporal separation between the first and subsequent passages of the contrast agent. Moreover, important physiologic information might be compromised by imposing an analytic equation to all measured concentration curves. This investigation proposes to exploit independent component analysis to minimize effects of recirculation in DSC. Results obtained from simulation, normal healthy volunteers, and acute stroke patients show that such a technique can greatly minimize the effects of recirculation despite a substantial overlap between the first passage and recirculation. This in turn should improve estimation of cerebral hemodynamics particularly when an overlap between the first passage and recirculation is suspected as in an ischemic lesion.

Adult↗

PubMed2006

Interactions between individual carbon nanotubes studied by Rayleigh scattering spectroscopy.

The electronic properties of single-walled carbon nanotubes (SWNTs) are altered by intertube coupling whenever bundles are formed. These effects are examined experimentally by applying Rayleigh scattering spectroscopy to probe the optical transitions of given individual SWNTs in their isolated and bundled forms. The transition energies of SWNTs are observed to undergo redshifts of tens of meVs upon bundling with other SWNTs. These intertube coupling effects can be understood as arising from the mutual dielectric screening of SWNTs in a bundle.

Journal Article↗

PubMed2006

Immunotherapy of tumors with protein vaccine based on chicken homologous Tie-2.

PURPOSE: Tie-2 is an endothelium-specific receptor tyrosine kinase known to play a key role in tumor angiogenesis. The present study explores the feasibility of immunotherapy of tumors by using a protein vaccine based on chicken Tie-2 as a model antigen to break the immune tolerance against Tie-2 in a cross-reaction between the xenogeneic homologous and self-Tie-2. EXPERIMENTAL DESIGN AND RESULTS: In this study, a chicken homologous Tie-2 protein vaccine (chTie-2) and a corresponding mouse Tie-2 vaccine as a control were prepared and the antitumor effect of these vaccines was tested in two tumor models (murine B16F10 melanoma and murine H22 hepatoma). Immunotherapy with chTie-2 was found effective in two tumor models. Autoantibodies against mouse Tie-2 were detected in sera of mice immunized with chTie-2 through Western blot analysis and ELISA assay. Anti-Tie-2 antibody-producing B cells were detectable by ELISPOT. Histologic examination revealed that autoantibodies were deposited on the endothelial cells of tumor tissues. Purified immunoglobulins from chTie-2-immunized mice could induce the apoptosis of human umbilical vein endothelial cells in vitro. Importantly, adoptive transfer of purified immunoglobulins led to antitumor effect in vivo; apparently, angiogenesis was significantly inhibited in these tumors. Furthermore, the antitumor activity and production of autoantibodies could be abrogated by depletion of CD4+ T lymphocytes. CONCLUSIONS: Our findings may provide a vaccine strategy for cancer therapy and show the potential utilization of interference with Tie-2 pathway.

Animals↗

PubMed2006

[Mean flow of saphenous vein graft and its influencing factors in patients performed coronary artery bypass grafting].

OBJECTIVE: To analyze the mean blood flow of saphenous vein (SV) graft and it's influencing factors in off-pump coronary artery bypass grafting by using transit-time flowmeter (TTFM). METHODS: Three hundred and twenty-six patients were studied. After all anastomoses were completed, and hemo-dynamic status was stable, TTFM was utilized to measure and record the SV flow wave, pulsatility index (PI), value of mean flow, diastolic and systolic peak flow, vascular resistance, insufficiency ratio and mean blood pressure. The standard conditions of good graft status to define the normal mean flow included good diastolic augmentation of blood wave, PI less than 5, intraoperative and postoperative no significant change in electrocardiogram, and smoothly postoperative recovery. RESULTS: Total mean flow calculated from that of all patients was (39 +/- 23) ml/min (10-153 ml/min). Majority mean value (60.1%, 196/326) was in the range of 20-50 ml/min. Statistics showed that mean flow was significantly related to vascular resistance and diastolic peak flow and PI rather than the other factors (r was -0.95, 0.77 and -0.51 respectively). CONCLUSIONS: For the patients, over 15 ml/min mean flow of SV graft is acceptable, and over 35 ml/min is satisfactory. The diastolic peak flow and vascular resistance are two important factors influencing mean flow.

Adult↗

PubMed2006

High throughput screening identified a substituted imidazole as a novel RANK pathway-selective osteoclastogenesis inhibitor.

Receptor activator of nuclear factor-kappaB (NF-kappaB) (RANK) plays a key role in the differentiation, activation, and survival of osteoclasts. Upon activation of RANK with RANK ligand (RANKL), osteoclast precursor cells differentiate into tartrate-resistant acid phosphatase (TRAP)-positive, multinucleated osteoclasts. To identify compounds that block osteoclastogenesis, a cell-based assay was developed using RAW264.7 cells stably transfected with a TRAP promoter-dependent reporter gene as a surrogate readout for differentiation. Described herein is the strategy for high throughput screening and subsequent secondary biological assays for hit triage, which resulted in the identification of compound 1, a 4-nitroimidazole derivative, that specifically inhibited RANKL-induced TRAP gene and protein expression. Compound 1 did not affect the tumor necrosis factor-alpha- or lipopolysaccharide-induced TRAP-luciferase response, suggesting selective inhibition of the RANKL-induced pathway. Reverse transcription polymerase chain reaction analysis confirmed the inhibition of expression of osteoclast marker genes, such as TRAP, cathepsin K, and carbonic anhydrase type II. Compound 1 did not inhibit the RANKL-induced activation of a NF-kappaB reporter gene, or p38 kinase activity, suggesting a mechanism of action downstream of NF-kappaB. Together, these results suggest that we have identified a RANK pathway-specific inhibitor able to block the RANKL-induced osteoclast differentiation process. The hit identification strategy described here can be applied to other cell-based assays using an indirect surrogate readout to improve success rates.

Acid Phosphatase↗

PubMed2006

[The antiangiogenic effect of DNA vaccine based on beta-defensin 2 fused with VE-cadherin].

OBJECTIVE: To explore the feasibility of generating beta defensin 2 fusion vaccine to break the immune tolerance of self antigens associated with angiogenesis. METHODS: PCR amplification of mature beta defensin 2 (Def) and extracelluar segment of Vascular Endothelial Cadherin (Cad) was conducted. (GGGS)3 was used as linker peptide for fusion plasmid(Def-Cad). All the three segments were inserted into pSecTag2B plasmid (pSec), and CT26 tumor cells were transfected. Expression was verified by RT-PCR and chemotaxis assay. The alginate bead model was used to study the antiangiogenic effect of fusion plasmid vaccination. RESULTS: All constructions were verified by sequencing and were found expressed in mammalian cell. The beta defensin 2 fusion protein had similar capacity to chemoattract dendritic cells as compared with nonfusion protein (P>0.05). The alginate bead assay revealed that the tumor-induced angiogenesis in fusion plasmid immunized mice was significantly suppressed when compared with that in nonfusion plasmid (P<0.01). CONCLUSION: An active immunization strategy based on beta defensin 2 fused with angiogenesis related antigen of endothelial can inhibit angiogenesis and may be a useful approach for cancer therapy.

Angiogenesis Inhibitors↗

PubMed2006

[Extract of Ginkgo biloba and quercetin inhibit angiotensin-II induced hypertrophy in cultured neonatal rat cardiomyocytes].

OBJECTIVE: To investigate the effect and related mechanisms of extract of ginkgo biloba (EGb) and quercetin (Que) on angiotensin II (AngII) induced hypertrophy in the primary cultured neonatal rat cardiomyocytes. METHODS: Primary cultured neonatal rat cardiomyocytes were treated with placebo (control), AngII (10(-6) mol/L), AngII + EGb (40 microg/ml), AngII + Que (4 microg/ml), AngII + captopril (10(-5) mol/L) and AngII + DPI [diphenylene iodonium chloride, NADPH inhibitor (10 micromol/L)] respectively. Total protein content of cardiomyocytes, cardiomyocytes size, superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were measured. The expression of phospho-Extracellular-signal regulated kinase 1/2, phospho-c-Jun N-terminal kinase and phospho-P38 were detected by Western blot. RESULTS: The total protein content and cell size of cardiomyocytes increased significantly in AngII treated cells and these effects could be blocked by EGb and Que. EGb and Que also enhanced the SOD activity and reduced the production of MDA. AngII significantly activated ERK1/2, JNK and P38 expressions and only JNK activation could be inhibited by Que and DPI. CONCLUSION: EGb and Que can inhibit AngII-induced cardiomyocyte hypertrophy through a ROS-dependent pathway. Que could also block the JNK activation induced by AngII.

Angiotensin II↗

PubMed2005

[A comparative study on grafts' blood flow after on-pump and off-pump coronary artery bypass surgeries].

OBJECTIVE: To compare the grafts' blood flow after on-pump and off-pump coronary artery bypass graftings. METHODS: Five hundred and forty-seven cases were studied, including four hundred and three cases undergoing off-pump coronary artery bypass (OPCAB, off-pump group) and one hundred and forty-four cases undergoing on-pump coronary artery bypass (CCABG, on-pump group). In all cases left internal mammary artery (LIMA) was routinely anastomosed to left anterior descending artery (LAD), and saphenous vein (SV) to the other target vessels in sequential mode when there were more than two anastomoses. After all anastomoses were completed and hemodynamic status was stable, transit time flow-meter was utilized to measure and record the grafts' flow wave, pulsatility index (PI), value of mean flow, diastolic and systolic peak flow, vascular resistance, insufficiency ratio and mean blood pressure. RESULTS: PI, insufficiency ratio and diastolic peak flow of LIMA in off-pump group were 2.7 +/- 1.8, (2.2 +/- 4.3)%, (46.8 +/- 2.7) ml/min respectively; those in on-pump group were 2.8 +/- 2.0, (3.4 +/- 3.1)% and (52.8 +/- 3.7) ml/min respectively. And those of SV in off-pump group were 2.8 +/- 0.1, (1.8 +/- 0.3)% and (85.8 +/- 3.2) ml/min respectively and those in on-pump group were 2.6 +/- 0.2, (1.3 +/- 0.2)% and (93.9 +/- 5.6) ml/min respectively. For both LIMA and SV grafts' blood flow there was no significant difference in PI, insufficiency ratio, diastolic peak flow and mean blood pressure in both groups (P > 0.05). The mean flow and systolic peak flow in off-pump group were significantly less than those in on-pump, while the vascular resistance in off-pump group was significantly greater than that in on-pump group (P < 0.01). CONCLUSION: There is no significant difference in grafts' patency between OPCAB and CCABG.

Adult↗

PubMed2005

Human T lymphocyte responses against lung cancer induced by recombinant truncated mouse EGFR.

The induction of active cellular responses against EGFR should be a promising approach for the treatment of those receptor-positive tumors. However, the immunity against EGFR is presumably difficult to elicit by vaccine based on self or syngeneic EGFR due to the immune tolerance acquired during the development in immune system. We proposed a model to break immune tolerance against self-EGFR through an altered immunogen source based on xenogeneic homologous EGFR. We have previously shown human EGFR as a xenoantigen could induce specific immune responses in mouse and cross-react with mouse EGFR, and resulted in therapeutic benefits for EGFR-positive mouse tumor. Here, we show a recombinant form of extracellular domain of mouse EGFR, in the presence of DCs, could activate human peripheral T cells to proliferate, secret IFN-gamma, the induced responses could cross-react with human EGFR and kill autologous EGFR-positive lung cancer cells which could be blocked by anti-CD8 and anti-MHC class I antibody. There is no detectable cytotoxical activity against lung tissue, liver tissue and kidney tissue derived from paracancerous normal tissue. These observations suggest that antitumor immunity induced by the truncated mouse EGFR may be provoked in a cross-reaction between mouse EGFR and self-EGFR, and may provide insight into treatment of EGFR-positive tumors through induction of the autoimmune responses against EGFR.

Animals↗

PubMed2005

[Expression of estrogen receptor and progesterone receptor in hilar cholangiocarcinoma and their clinical significances].

OBJECTIVE: To investigate the relationship between the expression of estrogen receptor (ER) and progesterone receptor (PgR) and histological type, pathological grading and clinical staging in hilar cholangiocarcinoma (HCCA). To evaluate their roles in the development of it. METHODS: ER and PgR were assessed in 42 specimens of HCCA by immunohistochemical assay. RESULTS: The positive rate of ER and PgR was 66.7% and 64.3%. The expression of ER and PgR was significantly different between poor and well tumor differentiation, as well as between papillary and sclerosing variant. CONCLUSION: The positive rate of ER and PgR was detected significantly in HCCA. They might be an important biological marker to evaluate the malignancy and prognosis of it.

Adult↗

PubMed2005

Combination of low-dose gemcitabine and recombinant quail vascular endothelial growth factor receptor-2 as a vaccine induces synergistic antitumor activities.

Vascular endothelial growth factor receptor-2 (VEGFR-2) has been shown to play a major role in inducing the full spectrum of VEGF biological response which is essential for tumor angiogenesis. We have demonstrated that immunotherapy of tumors with a vaccine based on quail homologous VEGFR-2 (qVEGFR) was effective in providing both protective and therapeutic antitumor immunity in several tumor models in mice. The purpose of this study was to determine whether the combination therapy of low-dose gemcitabine with qVEGFR as a vaccine could inhibit tumor growth to a greater extent. To test this concept, H22 hepatoma and Lewis lung carcinoma models were established in BALB/c mice and C57BL/6 mice, respectively. Mice were treated with either qVEGFR as a protein vaccine, gemcitabine, or both agents together. qVEGFR or low-dose chemotherapy treatment individually resulted in tumor inhibition to a certain extent.Remarkably, the combination therapy resulted in synergistic antitumor activity. Histological examination revealed that there was endothelial deposition of immunoglobulins within tumor tissues from mice treated with vaccine or combination therapy, especially intratumor angiogenesis was suppressed more significantly for the combination group. Also, ELISPOT analysis showed that mice treated with either qVEGFR alone or in combination with low-dose chemotherapy produced similar amount of anti-VEGFR antibody-producing B cells, which suggested that low-dose gemcitabine did not suppress the host's immune response, but potentiated the antitumor activity of the qVEGFR vaccine. Furthermore, TUNEL staining demonstrated a significant increase in the number of TUNEL-positive cells in the combination group compared with those of other groups. The observations may provide a new bio-chemotherapeutic approach for cancer.

Animals↗

PubMed2005

Dynamics of fluorescence dequenching of ostrich-quenched fluorescein biotin: a multifunctional quantitative assay for biotin.

We describe a simple and rapid quantitative assay for biotin and biotin conjugates. The assay is based on the kinetic analysis of the enhancement of fluorescence of streptavidin/fluorescein biotin complexes in the presence of biotin. The kinetic response of fluorescence enhancement is proportional to the concentration of biotin. Standard calibration curves based on the kinetic response are obtained and detection limits of approximately 10(-9)M are established. Because the assay is amenable for use in small volumes of 5-50 microL or bead-based assays, the detection limits can be extended to the femtomole range. Since the assay depends on kinetic analysis, routine quantitation can be achieved without reference to standard curves. The dynamic aspects allow the assay to be extended to a broader range of applications including its use as an indicator of reagent mixing in laminar-flow assays carried out in microfluidic devices.

Biotin↗