Fluorescein isothiocyanate-labeled insulin(FITC-insulin)has been widely used for bioanalytical applications.Due to the high cost of commercial FITC-insulin and tedious labeling procedures described in the literature,t...Fluorescein isothiocyanate-labeled insulin(FITC-insulin)has been widely used for bioanalytical applications.Due to the high cost of commercial FITC-insulin and tedious labeling procedures described in the literature,there is still a need to develop a cost effective,reliable and quick labeling method for insulin.The purpose of the present work was to develop a quick and affordable method for FITC labeling of human insulin and to determine the effect of different conjugations of FITC to human insulin on its permeability through the MDCK cell monolayer.FITC labeling of insulin gives mono-,di-or tri-conjugates depending on the reaction time and the molar ratio of FITC:insulin.Mono-conjugate with unlabeled insulin,mixture of di-and tri-conjugate,and tri-conjugate with very little amount of di-conjugate were synthesized in less than 4 h.Degree of conjugation had an effect on the permeability of insulin through the MDCK cell monolayer.Mono-conjugate had higher permeability than the unlabeled insulin due to increase in partition coefficient.However,tri-conjugate showed lower permeability than the unlabeled insulin due to the increase in molecular weight.展开更多
It has been reported that distal cerebrospinal fluidcontacting neurons（dCSF-CNs）can be detected by immunohistochemical assay using cholera toxin subunit B-conjugated horseradish peroxidase（CBHRP）.In the present st...It has been reported that distal cerebrospinal fluidcontacting neurons（dCSF-CNs）can be detected by immunohistochemical assay using cholera toxin subunit B-conjugated horseradish peroxidase（CBHRP）.In the present study,another two methods with CB alone or CB-conjugated FITC（CB-FITC）were used,and the results from the three methods were compared.Adult Sprague-Dawley rats were randomly divided into three groups with CB-HRP,CB or CB-FITC.Tracers were diluted to 30%in artificial cerebrospinal fluid and injected separately（in a volume of 3μL）into the lateral ventricle.Animals from the CB-HRP and CB groups were perfused 48 h after surgery while animals from the CB-FITC group were perfused 1,3,6,12,24 or 48 h after surgery.The brain was sectioned（40μm）for immunofluorescence and five sections with positive neurons were selected from each rat for neuron counting.Three clusters of positive neurons in a＇Y-like＇distribution were detected ventral to the cerebral aqueduct of rats from the three groups.No significant difference was observed among the quantitative data.In the CB-FITC group,stable staining was detected even at 6 h after injection.Taken together,lateral ventricle injection of CB/CB-FITC is a useful method for labeling dCSFCNs in rats.The CB-FITC method makes dCSF-CNs labeling much simpler and more convenient.展开更多
Exogenous DNA expressing green fluorescent protein( GFP) and labeled with fluorescein isothiocyanate( FITC) was used to transform the Chinese oak silkmoth Antheraea pernyi( A. pernyi)via sperm-mediated gene transfer( ...Exogenous DNA expressing green fluorescent protein( GFP) and labeled with fluorescein isothiocyanate( FITC) was used to transform the Chinese oak silkmoth Antheraea pernyi( A. pernyi)via sperm-mediated gene transfer( SMGT). Sperms entry into the female reproductive system and eggs were observed using fluorescence microscopy. The ability of A. pernyi sperms to uptake exogenous DNA was confirmed,and transfer of the exogenous DNA was shown by GFP expression in the transgenic eggs. Our result suggested that SMGT could also be used to directly generate transgenic A. pernyi expressing functional genes of interest.展开更多
文摘Fluorescein isothiocyanate-labeled insulin(FITC-insulin)has been widely used for bioanalytical applications.Due to the high cost of commercial FITC-insulin and tedious labeling procedures described in the literature,there is still a need to develop a cost effective,reliable and quick labeling method for insulin.The purpose of the present work was to develop a quick and affordable method for FITC labeling of human insulin and to determine the effect of different conjugations of FITC to human insulin on its permeability through the MDCK cell monolayer.FITC labeling of insulin gives mono-,di-or tri-conjugates depending on the reaction time and the molar ratio of FITC:insulin.Mono-conjugate with unlabeled insulin,mixture of di-and tri-conjugate,and tri-conjugate with very little amount of di-conjugate were synthesized in less than 4 h.Degree of conjugation had an effect on the permeability of insulin through the MDCK cell monolayer.Mono-conjugate had higher permeability than the unlabeled insulin due to increase in partition coefficient.However,tri-conjugate showed lower permeability than the unlabeled insulin due to the increase in molecular weight.
基金supported by grants from the National Natural Science Foundation of China (30871307, 81200862)the Fund of Science and Technology Innovation Team in Jiangsu Province, China (2009), Open Project Funds of the Jiangsu Key Laboratory of Brain Disease Bioinformation (Jsbl1107)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (12KJD320004)
文摘It has been reported that distal cerebrospinal fluidcontacting neurons（dCSF-CNs）can be detected by immunohistochemical assay using cholera toxin subunit B-conjugated horseradish peroxidase（CBHRP）.In the present study,another two methods with CB alone or CB-conjugated FITC（CB-FITC）were used,and the results from the three methods were compared.Adult Sprague-Dawley rats were randomly divided into three groups with CB-HRP,CB or CB-FITC.Tracers were diluted to 30%in artificial cerebrospinal fluid and injected separately（in a volume of 3μL）into the lateral ventricle.Animals from the CB-HRP and CB groups were perfused 48 h after surgery while animals from the CB-FITC group were perfused 1,3,6,12,24 or 48 h after surgery.The brain was sectioned（40μm）for immunofluorescence and five sections with positive neurons were selected from each rat for neuron counting.Three clusters of positive neurons in a＇Y-like＇distribution were detected ventral to the cerebral aqueduct of rats from the three groups.No significant difference was observed among the quantitative data.In the CB-FITC group,stable staining was detected even at 6 h after injection.Taken together,lateral ventricle injection of CB/CB-FITC is a useful method for labeling dCSFCNs in rats.The CB-FITC method makes dCSF-CNs labeling much simpler and more convenient.
基金Scientific Research Project for High Schools of the Educational Department of Liaoning Province,China(No.2008643)
文摘Exogenous DNA expressing green fluorescent protein( GFP) and labeled with fluorescein isothiocyanate( FITC) was used to transform the Chinese oak silkmoth Antheraea pernyi( A. pernyi)via sperm-mediated gene transfer( SMGT). Sperms entry into the female reproductive system and eggs were observed using fluorescence microscopy. The ability of A. pernyi sperms to uptake exogenous DNA was confirmed,and transfer of the exogenous DNA was shown by GFP expression in the transgenic eggs. Our result suggested that SMGT could also be used to directly generate transgenic A. pernyi expressing functional genes of interest.
