Measurement of Free Hemoglobin Percentage in Stored Packed Red Blood Cells Units by Colorimetric Method

Aims:To measure free hemoglobin percentage in stored packed red blood cells units by colorimetric method.Study Design:This is a descriptive, hospital based case study.Place and Duration of Study:Khartoum central blood bank during the period from June to September 2021.Methodology:A total of thirty-six packed red blood cells blood bags with Citrate-Phosphate-Dextrose-Adenine-one (CPDA-1) stored at 2-6°C for 35 days were withdrawn aseptically on days one; 14, and day 35. Free hemoglobin concentration was measured with Drabkin's method through digital photoelectric colorimeter in which the percentage of hemolysis was calculated, and PH values were measured by a PH meter (ADWA). Mean and standard deviation ofeach day were calculated by statistical package for social science (SPSS)computer program version 22.0.Results:The results showed statistically significant elevation in percentages of free plasma hemoglobin with prolongation of storage duration periods; day one compared with day 14 (P= 0.001), day one compared with day 35(P= 0.001) and day 14 compared with day 35 (P= 0.001). No significant correlation was observed between the degree of hemolysis in day 35 with PH values (P= 0.9).Conclusion:This study concluded that prolonged storage is associated with elevation of free plasma hemoglobin level indicative of progressive hemolysis.

Quantitative determination method and application of pharmaceutical adjuvant tween 80 / 中国中药杂志

Based on the fact that chromogenic reaction of blue complex, a reaction product which can be dissolved in organic solvents, can be realized by polyethoxy and ammonium thiocyanate in tween 80, a rapid and accurate way for the determination for tween 80 in pharmaceutical adjuvant was established in this study, providing reliable technical means for quality control of traditional Chinese medicine injections. Based on the study of reaction kinetics, chromogenic reaction temperature and time, as well as extraction of organic solvents and other key conditions were optimized, and Kumu injection was used as the test material for method validation and applicability investigation. It was finally determined that 3 mL ammonium thiocyanate solution was added in the sample solution, and the reaction was carried out in a boiling water bath for 2 h. After cooling to room temperature, 5 mL of dichloromethane was added to extract the chromogenic product. The absorbance value was measured at the wavelength of 623 nm to calculate the tween 80 content in the sample. Under optimized conditions, tween 80 solution showed a good linear relationship with the absorbance in the range from 0.8 mg to 3.0 mg. The linear regression equation was ＝0.258-0.047. The correlation coefficient was 0.999 6. Under the experimental conditions, the average recovery was 99.66%, and the precision RSD was less than 2.0%. The results showed that this method can quickly and accurately determine the content of tween 80 in Kumu injection, and it could be applicable to the quality control of traditional Chinese medicine injections.

Comparação entre três métodos analíticos para determinação de soro em leite cru refrigerado / Comparison of three analytical methods to determine serum in refrigerated raw milk

O objetivo deste experimento foi comparar três métodos analíticos para determinação de soro em leite cru refrigerado: cromatografia líquida de alta eficiência, ninidrina ácida e colorimétrico adaptado. Foram coletadas 100 amostras de leite cru refrigerado de tanques de expansão. Estas, quando submetidas à análise pelo método da ninidrina ácida, apresentaram 10 (14,7%) amostras negativas e 58 (85,3%) positivas. O teor médio de ácido siálico encontrado na técnica da ninidrina foi de 5,58(g/mL, com valor mais frequente de 2,70(g/mL. Das 68 amostras negativas pela cromatografia líquida de alta eficiência, duas foram positivas (2,94%) e 66 (97,06%) negativas, quando analisadas pelo método colorimétrico. A frequência relativa de amostras positivas foi de 32%, com a CLAE apresentando a maior média de soro (14,37%), seguida do método colorimétrico (5,28%) e o da ninidrina ácida (3,12%). A técnica de cromatografia líquida de alta eficiência diferiu dos métodos de ninidrina ácida e colorimétrico, enquanto os métodos da ninidrina e colorimétrico não diferiram entre si, podendo ambos serem utilizados como metodologias de triagem. Entre as três técnicas, a cromatografia líquida de alta eficiência foi a metodologia mais sensível na detecção e quantificação do soro em leite cru refrigerado.(AU)

The objective of this study was to compare three analytical methods to determine serum in refrigerated raw milk. High-performance liquid chromatography (HPLC), acidic and colorimetric ninhydrin methods were applied. A collection of 100 samples of raw milk from cooled expansion tanks took place. The results showed that 10 samples (14.7%) were negative and 58 (85.3%) were positive for the acidic ninhydrin method. The mean sialic acid content found in the ninhydrin technique was 5.58µg/mL, with a more frequent value of 2.70µg/mL. From all 68 HPLC negative samples, two were positive (2.94%) and 66 (97.06%) negative to the colorimetric method. The relative frequency of positive samples was 32%, HPLC had the highest mean serum levels (14.37%), followed by the colorimetric method (5.28%) and acid ninhydrin (3.12%). The high-performance liquid chromatography method was different from the acid and colorimetric ninhydrin methods. The ninhydrin and colorimetric methods were not different from each other, both of which could be used as screening methodologies. Among the three techniques, HPLC was the most sensitive methodology for the detection and quantification of serum in refrigerated raw milk.(AU)

Study on Determination Method of Total Flavonoids in Gansu Astragali Radix and ;Hedysarum Polybotrys / 中国中医药信息杂志

Objective To study the determination method of total flavonoids in Gansu Astragali Radix and Hedysarum Polybotrys. Methods Calycosin glycosides etc. was selected as reference substances, comparison on the difference of absorption curves was done by ultraviolet spectroscopy and colorimetric method (NaNO2-Al(NO3)3-NaOH, AlCl3, Mg(Ac)2, NaOH, phosphomolybdic acid, HCl-Mg power). Results With colorimetric method, the maximum absorption wavelength of referrence and the test was inconsistent. The absorption peak shape was also different. With UV method, Calycosin glycosides in band Ⅱ (260 nm) showed a shoulder absorption. Astragali Radix and Hedysarum Polybotrys also showed characteristic shoulder absorptions in band Ⅱ with absorption wavelength at 263 nm and 265 nm. So the sample absorption wavelength is basically the same as that of the control sample. Conclusion Colorimetries usually used for determination of total flavonoids are not suitable for the comparison determination of Gansu Astragali Radix and Hedysarum Polybotrys. It is suitable for determining the contents of total flavonoids in samples by UV spectrophotometry at the band Ⅱ, which is the characteristic absorption band of isoflavone compound.

Performance verification of three ischemia-modified albumin reagents / 国际检验医学杂志

Objective To verify the performance of three kinds of ischemia‐modified albumin(IMA) reagents .Methods The performance of three IMA reagents(labeled as reagent A ,B ,C) using colorimetric method from Shanghai Aikang Biotechnology Co .,Ltd .,Zhejiang Kuake Bioscience Technology Co .ltd .and Beijing Jiuqiang Biotechnology Co .,Ltd .were assessed by using O‐lympus AU5800 automatic biochemistry analyzer .According to the National Committee for Clinical Laboratory(NCCLS) EP6‐A , EP15‐A and EP7‐A documents and WS/T 420‐2013 verificationof analytical performance of quantitative kits by clinical labo‐ratory ,the precision ,linearity range ,accuracy and anti‐interference capability were assessed .Results The within‐run coefficient of variations(CVs) of reagent A ,B and C were 0 .59% -0 .82% ,0 .27% -0 .54% and 0 .62% -0 .69% respectively .The between‐run CVs of reagent A ,B and C were 0 .98% -1 .74% ,0 .99% -1 .01% and 0 .71% -0 .78% ,respectively ,which were lower than decla‐rations of these reagent kits .The linearity range of reagent A ,B and C were 11 -142 U/mL(r2 = 0 .993) ,10 -120 U/mL(r2 =0 .996) ,14-123 U/mL(r2 =0 .992) respectively ,which showed good linearities .About interference tests ,no remarkable interfer‐ences(all Bias were less than ± 10% ) of reagent A ,B and C were detected when Vitamin C≤10 mg/dL ,hemoglobin≤200 mg/dL , bilirubin≤40 mg/dL and triglyceride≤500 mg/dL .Conclusion The three IMA reagents show high precision ,which could meet clinical requirements ,nevertheless ,differences of anti‐interference capabilities are observed in these three reagents .

Saponin Accumulation in Flower Buds of Panax notoginseng / 中草药·英文版

Objective: Panax notoginseng is an important Chinese medicinal plant. Saponin accumulation is higher in the flower buds than in the other parts of P. notoginseng. However, the flower bud compositions have not yet been quantified. The aim of this study is to investigate the formation and accumulation of saponins in the flower buds of P. notoginseng from different populations and at different growth years. Methods: Fourteen types of P. notoginseng with different growing durations and from different areas of Wenshan County, Yunnan Province were collected. We separated P. notoginseng individually into the flower buds, stems, leaves, and roots at the places where it has the highest saponin content. An efficient high-performance liquid chromatography (HPLC) method was developed for simultaneously quantifying two active saponins, ginsenoside Rb1 and ginsenoside Rb3, in the flower buds of P. notoginseng. The total saponin content was determined by using a quantitative vanillin-sulfuric acid colorimetric method. HPLC method was used to establish the fingerprints of 13 saponins and then quantify the composition in the whole plant of P. notoginseng. Results: The saponin contents of different parts differ significantly, and the total saponin content and those of Rb1 and Rb3 do not entirely correlated. The flower buds of P. notoginseng contain 27.79% of total saponins, which is the highest saponin content in the whole plant. Fingerprint result showed that different saponins were appeared in different parts of the plant, i.e. flower buds, stems, leaves, and roots. Conclusion: The saponin contents from the flower buds of P. notoginseng vary depending on the growth area and duration. The fingerprints show that the saponin contents and compositions vary depending on the part of P. notoginseng. These results are useful for the pharmacological evaluation and quality control of P. notoginseng.

Effects of different steaming methods on saponins in taproots of Panax notoginseng / 中草药

Objective: To research the effect of different steaming methods on the saponins content in the taproots of Panax notoginseng. Methods: Colorimetric method is used to determine the content of total saponins in the taproot of P. notoginseng, using high performance liquid chromatography (HPLC) method for determining the content of monomer saponins in the taproot of P. notoginseng. Results: The contents of total saponins, notoginsenoside R1, and ginsenosides Rg1, Re, Rb1, and Rd in the taproot of P. notoginseng have been reduced to some extent, while the contents of five kinds of monomer saponins of ginseng, i.e. ginsenosides Rh1, Rh4, Rk3, 20(S)-Rg3, and 20(R)-Rg3 all have been increased in varying degrees after steamed. Conclusion: The different steaming methods have the different influences to saponin composition in the taproot of P. notoginseng, the contents of total saponins and five main saponins could decrease and new generated monomer saponins could increase associated with the steaming time and temperature. This method can be used for the determination of the contents of saponin compounds and quality control in processed notoginseng products, and provide the basis for the study on the correlation between notoginseng "sheng da shu bu" and substance changes, while provide the certain theory basis for researching the accumulation rule of rare saponins.

Colorimetric Determination of Lactate Dehydrogenase on Paper-Based Microwell Arrays Microfluidic Device / 分析化学

A low-cost, simple, sensitive detection method of lactate dehydrogense ( LDH) was developed on paper-based microwell arrays microfluidic device. The phenazine methyl sulfate/nitrotetrazolium blue chloride ( PMS/NBT) detection system was used for LDH detection and the colorimetric results were recorded by both Gel Documentation System and a common camera. Under the optimized conditions, the colorimetric intensity showed a linear correlation to the activity of LDH in the range of 10 to 150 U/L with a limit of detection (LOD) of 9. 44 U/L (3σ) by Gel Documentation System;and the linear range was 15-150 U/L by camera with a LOD of 12. 36 U/L (3σ). Foremost, it was found that human serum albumin (HSA) had an effect on the colorimetric enhancement in this detection system. This low-cost, portable paper-based analytical platform could be suitable for the application in the point-of-care with high sensitivity and reproducibility.

Determination of the main phenolic in Clerodendranthus spicatus from different areas by colorimetric method / 国际药学研究杂志

Objective To choose an appropriate coloured system and develop a method for the determination of the main phenolic in Dai Medicine -Clerodendranthus spicatus from different areas. Methods The main phenolic in Clerodendranthus spicatus from 19 areas was determined at 500 nm wavelength, with rosmarinic acid as reference and sodium nitrite-aluminum nitrate-sodium hydroxide as colour-developing system. Results Rosmarinic acid presented good linear relationship (r2=0.9993) in the concentration range of 8.792-17.584μg/ml.The average recovery was 100.73%and RSD was 0.85%.The content of the main phenolic in Clerodendranthus spicatus ranged from 1.16 % to 3.49 %. Conclusion The method is appropriate for the determination of the main phenolic in Clerodendranthus spicatus. The main phenolic content in samples from Yunnan province is relatively high.

Determination of the main phenolic in Clerodendranthus spicatus from different areas by colorimetric method / 国际药学研究杂志

Objective To choose an appropriate coloured system and develop a method for the determination of the main phenolic in Dai Medicine -Clerodendranthus spicatus from different areas. Methods The main phenolic in Clerodendranthus spicatus from 19 areas was determined at 500 nm wavelength, with rosmarinic acid as reference and sodium nitrite-aluminum nitrate -sodium hydroxide as colour-developing system. Results Rosmarinic acid presented good linear relationship (r2 =0.9993) in the concentration range of 8.792-17.584 μg/ml.The average recovery was 100.73% and RSD was 0.85%.The content of the main phenolic in Clerodendranthus spicatus ranged from 1.16 % to 3.49 %. Conclusion The method is appropriate for the determination of the main phenolic in Clerodendranthus spicatus. The main phenolic content in samples from Yunnan province is relatively high.

Novel analytical method development for some amide group containing drugs using Bougainvillea spectabilis bract extracts

OBJECTIVE@#To develop and validate a simple, accurate and precise colorimetric method using Bougainvillea spectabilis (B. spectabilis) bract color previously not exploited for estimation of amide group containing drugs i.e. lidocaine and ranolazine in pharmaceutical formulations.@*METHODS@#Methanolic extract of B. spectabilis was prepared and evaluated for stability of its color at different pH and temperature for a period of 3 weeks. The accuracy and reliability of the proposed method was ascertained by evaluating various validation parameters like linearity, precision, limit of detection, limit of quantitation and specificity according to International Conference on Harmonization guidelines. About 0.5% of B. spectabilis bract color was added to the working standard solutions of the drugs separately and after formation of color complex, and absorbances were noted at 418 nm.@*RESULTS@#For color complexes of lidocaine and ranolazine, linearity was found to be in the range of 4 to 24 and 5 to 25 μg/mL respectively. The % relative standard deviation was found to be within specification limits. Presence of lone pair of electron on nitrogen of amide group of both drugs shows basic nature, contributed in formation of color complex between amide and the color pigment obtained from B. spectabilis bracts.@*CONCLUSIONS@#It can be concluded that the method is simple, accurate, economic, and rapid hence can be employed for routine analysis.

Methodology exploration of test for haemolysis and agglomeration of colored injections and emulsion injections / 中国药学杂志

OBJECTIVE: To supplement and improve the method of haemolysis and agglomeration test of Pharmacopoeia of the People's Republic of China (2010 edition) thus to exclude the interference of colored injections and emulsion injections on haemolysis test.

Novel analytical method development for some amide group containing drugs using Bougainvillea spectabilis bract extracts

Objective: To develop and validate a simple, accurate and precise colorimetric method using Bougainvillea spectabilis (B. spectabilis) bract color previously not exploited for estimation of amide group containing drugs i.e. lidocaine and ranolazine in pharmaceutical formulations. Methods: Methanolic extract of B. spectabilis was prepared and evaluated for stability of its color at different pH and temperature for a period of 3 weeks. The accuracy and reliability of the proposed method was ascertained by evaluating various validation parameters like linearity, precision, limit of detection, limit of quantitation and specificity according to International Conference on Harmonization guidelines. About 0.5% of B. spectabilis bract color was added to the working standard solutions of the drugs separately and after formation of color complex, and absorbances were noted at 418 nm. Results: For color complexes of lidocaine and ranolazine, linearity was found to be in the range of 4 to 24 and 5 to 25 μg/mL respectively. The % relative standard deviation was found to be within specification limits. Presence of lone pair of electron on nitrogen of amide group of both drugs shows basic nature, contributed in formation of color complex between amide and the color pigment obtained from B. spectabilis bracts. Conclusions: It can be concluded that the method is simple, accurate, economic, and rapid hence can be employed for routine analysis.

Comparison of adherence ability of bacteria on the surface of rigid gas-permeable contact lens made with different materials / 中华实验眼科杂志

Background Wearing contaclenincreasethe risk of infection of the cornea.Some studieshowed the gas-permeability of materialused foconstructing corneal contaclenione of the contributing factorrelated to corneal health.Objective Thistudy wato observe the in vitro adherence ability of differenbacterito rigid gas-permeable contaclense(RGP-CL) made with varioumaterials.MethodContaclensemade with hexafocon,enflufocon opolymethyl methacrylate (PMMA) were placed into Staphylococcuaureus,Staphylococcuepidermidis,oPseudomonaaeruginosbacterial suspension(0.5 MCF) fo24 hours.The strength of bacterial adherence watested and studied by the methyl thiazolyl tetrazolium (MTT) colorimetrimethod based on absorbance (value),and the vortex method waused to calculate the colony forming units.The bactericlump formation waexamined with scanning electron microscope (SEM).ResultMTcolorimetrimethod showed thathe adherence ability of Staphylococcuaureuto hexafocon (value) wasignificantly lowethan thato enflufocon and PMMA,respectively (q=7.379,8.207,P＜0.01),buno significandifference wafound in the adherence ability of Staphylococcuaureubetween enflufocon and PMM(q =0.828,P＞0.05).The adherence ability of Staphylococcuepidermidito XO and enflufocon walowethan thato PMM(q =14.000,12.800,P＜0.01),buno significandifference wafound between the adherence of Staphylococcuepidermidito hexafocon and enflufocon material (q =1.200,P＞0.05).There wano significandifference in the adherence ability of Pseudomonaaeruginosto all three material(F=2.155,P=0.138).The vortex method presented the colony forming unitof Staphylococcuaureuto hexafocon,enflufocon and PMMwith (37.9± 1.5)×106,(49.9±2.2)×106 and (67.4± 1.6)×106,respectively,with significandifference among them (F =206.240,P＜0.01),showing the lowesvalue in hexafocon,the highesvalue in PMMand middle value in enflufocon (q=11.650,28.640,16.990,P＜0.01),Moreover,colony forming uniof Staphylococcuepidermidito hexafocon,enflufocon and PMMwa(7.9 ± 1.3) × 106,(10.5 ± 1.5) × 106,(11.2 ±1.2) × 106,respectively.And thaof hexafocon walowethan one of the PMMmaterial (q =5.060,P＜0.05).No significandifference wafound between hexafocon and enflufocon nobetween hexafocon and PMM(q =3.290,1.770,P＞0.05).In addition,the resultthacorresponded to the vortex method were seen in the MTcolorimetriassay (F =0.232,P =0.799).SEM examination showed dispersed population of Staphylococcuaureuand Staphylococcuepidermidion the surfaceof hexafocon and enflufocon;while much more Staphylococcuaureuand Staphylococcuepidermidiadhered on the surface of PMMA,forming net-like appearance.Conversely,high numbeof Pseudomonaaeruginoswaseen on the surface of all three materials,withounoticeable differencein the bacterial shape and quantity on each of the material.ConclusionThe adherence ability of bacterito PMMistrongethan thaof hexafocon and enflufocon,and gas-permeable material of RGP-CL doenoimpacthe adherence ability of bacteria.

Detection of BRAF Mutation on Fine Needle Aspiration Biopsy Specimens Using the Colorimetric Mutation Detection Method

PURPOSE: The detection of papillary thyroid carcinoma (PTC) is increasing these days; however, there is currently no satisfactory definitive preoperative diagnostic method. Fine-needle aspiration cytology (FNAC) is now the most accurate method to diagnose PTC preoperatively. It is known that the specificity of BRAF mutation is high in papillary thyroid carcinoma. Therefore, detection of BRAF mutation using a FNAC slide can be helpful to diagnose PTC preoperatively. METHODS: 13 patients with benign disease, 36 patients with PTC and 23 patients with an indeterminate diagnosis as determined histologically on the FNAC slide were evaluated to detect BRAF mutation with using FNAC slides and intraoperative fresh tissue. RESULTS: Mutation was detected using direct sequencing and the colorimetric method. The frequency of BRAF mutation was 86.3% for all the PTC cases. The concordance between the colorimetric method and direct sequencing was 57.1%. During DNA extraction from the FNAC slide, the DNA damage is so severe that direct sequencing is succeeded in only one case. CONCLUSION: We have to take measures to overcome and prevention DNA damage during extraction. The colorimetric method is not reliable.

Degradation Kinetics of Sinomenine Hydrochloride Aqueous Solution / 中国药房

OBJECTIVE:To investigate the degradation kinetic characteristics of Sinomenine hydrochloride aqueous solution.METHODS:The colorimetric method was used to determine the degradation kinetic parameters of Sinomenine hydrochloride aqueous solution under various pH solutions,various ionic strength and various dielectric constant conditions.RESULTS:With comparative regression analysis of linear fitting,the degradation kinetic order of Sinomenine hydrochloride aqueous solution was determined as n=1.The higher the pH in Sinomenine hydrochloride aqueous solution was,the higher the degradation kinetic rate constant was.The Sinomenine hydrochloride aqueous solution degraded slowly at the field of lower pH(pH5).The higher the ionic strength of Sinomenine hydrochloride aqueous solution was,the higher the degradation kinetic rate constant was.As the dielectric constant of solution increased,so did the degradation kinetic rate constant.CONCLUSION:It was found that the degradation of Sinomenine hydrochloride followed apparent first-order kinetics.The degradation kinetic rate was affected by pH remarkably and positively correlated with ionic strength and dielectric constant.

Evaluation of a Colorimetric Antifungal Susceptibility Test by 2,3-Diphenyl-5-Thienyl-(2)-Tetrazolium Chloride for Fluconazole in Candida Species Isolated from Clinical Specimens / 대한임상미생물학회지

BACKGROUND: The aims of this study were to evaluate the colorimetric antifungal susceptibility test to fluconazole using 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride (STC) for various Candida species isolated from clinical specimens and to compare the results with those of the CLSI M27-A2 standard method. METHODS: The fluconazole MICs for 204 clinical Candida isolates consisting of 100 C. albicans, 45 C. glabrata, 28 C. tropicalis, 22 C. parapsilosis, and 9 other Candida species were determined by the CLSI and STC colorimetric methods. RESULTS: All 204 Candida strains were grown on the growth control wells of CLSI standard plates, but 26 Candida strains (6 C. albicans and 20 C. tropicalis) were not grown on those containing STC. Therefore, those 26 Candida strains were excluded from the comparison of MICs in this report. Overall, the STC visual and spectrophotometric readings of fluconazole MICs showed 96.1% (N=171) and 89.9% (N=160) accordance with those obtained by the CLSI standard method within 2 dilutions, respectively. The STC visual reading of C. albicans showed 76.6, 92.6, and 95.8% accordance with the CLSI standard method within 1, 2, and 3 dilutions, respectively. The agreement between the two endpoint determinations of the STC colorimetric method (visual and spectrophotometric readings) was excellent, with 170 of the 178 MICs within 2 dilutions. CONCLUSION: The STC colorimetric method to determine the MIC for Candida species except C. tropicalis showed high levels of agreement with CLSI method. And also, it is useful with objective and easy interpretation.

Content Determination of Polysaccharide in Pinellia Tuber / 中国中医药信息杂志

Objective To determine the content of polysaccharide of prepared pinellia tuber. Methods The content was determined by sulfuric acid-anthrone colorimetric method with wavelength at (624?1)nm. Results The content of polysaccharide was 2.533 mg/g in prepared pinellia tuber. The average recovery was 99.54% and RSD was 1.69%. Conclusion The methods was simple, steady and reproducible.

Cloning of the Phosphatidylserine Synthase Gene and Its Secretive Expression in Bacillus subtilis / 中国生物工程杂志

The gene encoding the phosphatidylserine synthase in Escherichia coli K12 Sgal-(ExPASy P23830) was amplified by PCR. After DNA sequence analysis, it was inserted into the inducible expressive shuttle vector pBES of Bacillus subtilis, which was constructed in the lab, and the recombinant plasmid pBES-pss was transformed into competent cells of the Bacillus subtilis strain DB104. The positive transformant DB104 (pBES-pss) was grown on Bacillus subtilis common fermentation medium, which contained 30?g/ml kanamycin. After 2 hours cultivation, sucrose was added and increased to the final concentration of 2% for induction and this phosphatidylserine synthase was secreted into the medium. The result of SDS-PAGE showed that the molecular weight of the protein was 52kDa and the result of enzyme coupling colorimetric method showed that the enzyme activity was 1.50U/ml. The recombinant Bacillus subtilis has increased the yield of phosphatidylserine synthase which will be used for industrial biosynthesis of phosphatidylserine.

Comparative study on the effects of collagenase inhibitor in different eye drops / 眼科新进展

Objective　To investigate, compare and filtrate the collagenase inhibitor effects among six kinds of eye drops for clinical use.Methods　The collagenase inhibitor’s effects were detected by rat's collagen and collagenase with comassie brilliant blue colorimetric method.Results　The inhibitting collagenase effects among six kinds of eye drops were different: the effect of cartopril was the strongest；the acetylcysteine and sodium edetate were more strong and the sodium citrate, sodium hyposulfite and tetracycline were less strong.Conclusion　 0.5g*L-1cartopril eye drops has stronger efficacy to inhibit collagenase, with less side effect or stimulation，more convenient resource and preparation than other eye drops.