人工气候室用于测定作物群体光合作用的方法

以我院所建人工气候室,构建了用于测定与分析作物群体光合作用的方法和体系,以网纹甜瓜为材料进行了不同温度、光照和CO2等环境条件下群体光合速率的测定和分析,并用作物模拟模型对测定结果进行了比较和检测,结果表明所建体系用于测定作物群体光合作用的效果良好。     

油桐尺蠖核型多角体病毒的空斑测定

在油桐尺蠖卵巢细胞系上对油桐尺蠖核型多角体病毒(BsNPV)进行了空斑测定。用此方法测定了BsNPV的感染力,并将所得的结果与其TCID_(50)进行比较,结果显示这两种方法在测定病毒感染力时敏感性相似。     

啤酒中风味物质双乙酰含量的测定

采用Turbotherm Vap40自动定氮仪进行啤酒的蒸馏操作以测定啤酒中双乙酰含量,测定结果与国标法进行了对照,结论是Turbotherm Vap40自动定氮仪可以替代国标法中的双乙酰蒸馏装置进行啤酒中双乙酰含量的测定。     

石墨活性膜 IgG 免疫传感器的研制

用电化学聚合和戊二醛交联的方法,将羊抗人 IgG 抗体固定在石墨电极表面,研制成固态活性膜直接 IgG 免疫传感器,对人血清 IgG 进行了测定.并对免疫传感器的测定、再生、保存条件、精密度、测定范围和选择性及与 IgG 免疫扩散测定法的相关性进行了研究.结果表明,石墨活性膜 IgG 免疫传感器具有操作简单、快速、测定准确度和精密度高的特点,为今后免疫传感器的研制提供了一种新的方法.     

分光光度法测定苦参中微量元素铜的含量

采用分光光度法测定了苦参中微量元素铜的含量,探讨了测定条件,并与火焰原子吸收光度法进行了对比。结果表明,两种方法的测定结果吻合,平均回收率分别为95.2%和101.6%,相对标准偏差分别为1.82%和1.10%,结果可靠,特别是分光光度法仪器价格低,操作简便,适用范围广,可用于实际样品的测定。     

甘油转化生产1,3-丙二醇发酵液中甘油含量的测定

对文献介绍滴定法测定甘油的方法进行了改进,使之能够用于1,3－丙二醇发酵液中甘油含量测定。实验表明,化学滴定法测定结果具有较好的准确性和重复性,与酶法和变色酸比色法相比,测定结果接近,化学滴定法测定发酵液中甘油含量是一个较为经济简便的方法。     

杀虫药剂生物测定原理与实践

本文从生物测定的基本原理、试验靶标的选择、杀虫药剂毒力测定标准化和统计分析等方面对杀虫药剂的毒力测定进行了规范性综述,为进行标准的生物测定提供依据和参考。     

荧光法测定发酵液中的苯丙氨酸含量

本文介绍荧光测定微生物发酵液中苯丙氨酸含量的方法。它的原理是苯丙氨酸和茆三酮在pH5.8的酸性二肽溶液中能形成荧光产物。所产生的荧光再被铜离子增强并稳定之后,即可用荧光分先光度计进行测定。测定的激发光波长为365mm,发射光波长为500nm。本文对荧光测定的条件进行了研究,结果表明荧光测定发酵液中苯丙氨酸的含量是一种专一性强,灵敏度高,操作简便的微量分析方法。     

人血清铁的化学发光法测定

研究了鲁米诺化学发光体系测定痕量铁的条件.在选定条件下测定铁(Ⅲ)的线性响应范围为0.2 ng/ml-0.1 μg/ml,检出限为0.0014 ng/ml,对含0.5 ng/ml的试样进行10次重复测定,其结果的变异系数为3.4％.对二十几种常见阴阳离子的干扰情况进行了试验和讨论.将本方法应用于正常人血清中微量铁的测定,结果较满意.     

五种α─淀粉酶测活方法的比较研究

对常用的五种α─淀粉酶活力测定方法进行了比较。研究了酶的稀释倍数和反应时间等因素对α─淀粉酶活力测定的影响,确定了α─淀粉酶活力测定的最佳条件。通过比较研究,认为Ｙｏｏ改良法是α─淀粉酶活力测定的最佳方法,并确定了各方法不同活力单位之间的相互换算关系。     

Identification and elimination of heterophilic antibody interference during antibody pair screening

A sensitive and simple technique for the negative detection of lipopolysaccharides (LPSs) following polyacrylamide gel electrophoresis (PAGE) using eosin B (EB) was developed. After electrophoresis, gels were fixed, stained, and developed within 30 min to achieve transparent and colorless LPS bands under opaque gel matrix background. As low as 20 to 40 ng of total LPSs could be detected, which is 4-fold more sensitive than those of the widely used silver stain developed by Fomsgaard and coworkers and imidazole-zinc (IZ) negative stain. For its sensitivity and brevity, this stain may be a practical method for LPS determination in the routine laboratory.     

DNA sequence analysis by MALDI mass spectrometry.

Conventional DNA sequencing is based on gel electrophoretic separation of the sequencing products. Gel casting and electrophoresis are the time limiting steps, and the gel separation is occasionally imperfect due to aberrant mobility of certain fragments, leading to erroneous sequence determination. Furthermore, illegitimately terminated products frequently cannot be distinguished from correctly terminated ones, a phenomenon that also obscures data interpretation. In the present work the use of MALDI mass spectrometry for sequencing of DNA amplified from clinical samples is implemented. The unambiguous and fast identification of deletions and substitutions in DNA amplified from heterozygous carriers realistically suggest MALDI mass spectrometry as a future alternative to conventional sequencing procedures for high throughput screening for mutations. Unique features of the method are demonstrated by sequencing a DNA fragment that could not be sequenced conventionally because of gel electrophoretic band compression and the presence of multiple non-specific termination products. Taking advantage of the accurate mass information provided by MALDI mass spectrometry, the sequence was deduced, and the nature of the non-specific termination could be determined. The method described here increases the fidelity in DNA sequencing, is fast, compatible with standard DNA sequencing procedures, and amenable to automation.     

Determination of sulfhydryl groups and disulfide bonds in a protein by polyacrylamide gel electrophoresis

A general method by polyacrylamide gel electrophoresis for the determination of sulfhydryls and disulfides in a protein was developed. The method included a two-step alkylation procedure: the first step consisted of alkylation of the sulfhydryl groups with iodoacetic acid in the presence and absence of 8 M urea; the second step consisted of alkylation of the disulfide groups with iodoacetamide after reduction with a thiol. By high-pH urea gel electrophoresis, all the half-cystine residues in a protein could be categorized into three states: reactive sulfhydryls, nonreactive sulfhydryls, and disulfide bonded. The particular advantage of the method is that the states of half-cystines in different protein species can be analyzed independently both in isolated protein and in biological translation systems.     

Thin layer gel filtration as a method for routine steroid receptor binding studies

A new technique is introduced which allows the quantitative determination of radioactively labeled substances from thin layer gel filtration (TLG). For gel filtration sephadex G-100 on a glass plate coated with a cellulose film was used. Together with the Sephadex layer the celluose film could be cut easily into strips and placed into vials for counting. The method was satisfactory with binding studies of steroid hormones on the prostatic androgen receptor. Because of simplicity, speed, and economical reasons this method could be used as a routine receptor assay.The binding constant of dihydrotestosterone (DHT) receptor complex was determined as K_a = 0.36 × 10⁹ liter/mole. The relative binding affinity of the antiandrogen cyproterone acetate was found to be 0.23.     

An insoluble chromolytic substrate for the determination of proteolytic activity

A new insoluble chromolytic substrate for the determination of proteolytic activity was prepared by immobilization of dyed casein into the structure of polyacrylamide gel. The prepared substrate could detect approximately 0.1 microgram of trypsin per ml. The spontaneous leakage of dyed casein molecules in water solutions was negligible.     

Gas chromatographic method for the determination of urinary acetylpolyamines

A gas chromatographic method was developed for the determination of monoacetylputrescine, monoacetylcadaverine, N¹-acetylspermidine and N⁵-acetylspermidine in human urine. The amines were isolated from urine by silica gel column chromatography. 1, 10-Diaminodecane was used as internal standard. The amines were reacted with ethyl chloroformate in aqueous medium to four ethyloxycarbonyl derivatives prior to application to gas chromatography using a flame ionization detector. Separation and determination of the derivatives were carried out on a Uniport HP column (1.0 m) impregnated with 0.5% SP-1000 under temperature-programmed conditions. The monoacetylpolyamines could be measured accurately at the nanomole level. The method was used for the determination of the monoacetylpolyamines in urine of healthy volunteers. The values obtained were in the range of the published data.     

Ontogeny of haemoglobin polymorphism in cod

Haemoglobins of 0-group cod from 30 to 150 mm length were analysed by agar gel electrophoresis and isoelectric focusing to identify the lower size limit for determination of the haemoglobin polymorphisms in cod; both the main system which has been known for more than 30 years and the recently described subgroups. The juvenile fish studied had higher concentration of the HbII-component (split into three bands at these fish sizes) compared to older fish. The main haemoglobin types could be distinguished clearly and reliably at a fish size of about 35 mm and above. The subgroups of the HbI-components, however, could not be identified reliably until the cod were about 80 mm.     

Characteristics of the heat-stable enterotoxin of NAG vibrios

Cell-free culture filtrate boiled for 15 minutes has been found to retain its biological activity in various experimental models used for the determination of the toxicogenicity of cholera vibrio filtrates. During gel filtration of the concentrated filrate o. NAG vibrio, strain NO. 9852, through Sephadex G-75 toxic activity could be detected in the free volume of the column, which was indicative of the fact that the molecular weight of the thermostable enterotoxin was about 70,000 daltons and greater. The methods of gel diffusion and aggregated hemagglutination have been used to show that the thermostable enterotoxin of NAG vibrio No. 9852 is immunologically unrelated to cholerogen. Some data obtained in experimental models suggest that the thermostable enterotoxin probably differs from cholera enterotoxin in the mechanism of its action.     

Purification of a non-chloroplastic α-glucan phosphorylase from spinach leaves

The non-chloroplastic -glucan phosphorylase (EC 2.4.1.1) from spinach leaves has been purified to homogeneity as revealed by dodecylsulfate gel electrophoresis. Both purification and separation from the chloroplastic phosphorylase were achieved by chromatography on Sepharose-bound dextrin. The chloroplastic phosphorylase did not bind to Sepharose-dextrin and was removed from the column by washing with buffer, as verified by polyacrylamide gel electrophoresis of the buffer eluate and by chromatography of a preparation from isolated intact chloroplasts. The non-chloroplastic phosphorylase did bind to a high extent to Sepharose-dextrin and could be eluted by a dextrin gradient. Based on dodecylsulfate gel electrophoresis and pyridoxal phosphate determination, a molecular weight of about 90,000 was found for the monomer. Molecular-weight determination by porosity density gradient electrophoresis and gel filtration on Sephadex G-200 suggested that the native enzyme is a dimer, as are other phosphorylases.Abbreviations DEAE diethylaminoethyl - EDTA ethylenediamine tetraacetic acid - G1P glucose 1-phosphate - HEPES N-2-hydroxyethylpiperazine-N-2-ethanesulphonic acid - PMSF phenylmethyl sulphonyl fluoride - SDS sodium dodecylsulfate - Tris Tris (hydroxymethyl)aminomethane Dedicated to Professor Dr. A. Pirson on the occasion of his 70th birthday