Hampton蛋白结晶试剂盒HEPES Buffer

上海金畔生物代理Hampton research品牌蛋白结晶试剂耗材工具等,我们将竭诚为您服务,欢迎访问Hampton research官网或者咨询我们获取更多相关Hampton research品牌产品信息。

Products > Optimize Reagents > Optimize – Buffers > HEPES Buffer

HEPES Buffer

应用

  • Crystallization grade HEPES buffer for formulating screens or for optimization
  • 用于配制筛选或优化的结晶级 HEPES 缓冲液

特征

  • Sterile filtered
  • Formulated in Type 1+ ultrapure water: 18.2 megaohm-cm resistivity at 25°C, < 5 ppb Total Organic Carbon, bacteria free (<1 Bacteria (CFU/ml)), pyrogen free (<0.03 Endotoxin (EU/ml)), RNase-free (< 0.01 ng/mL) and DNase-free (< 4 pg/µL)无菌过滤
    在 1+ 型超纯水中配制:25°C 时电阻率为 18.2 兆欧厘米,总有机碳 < 5 ppb,无细菌(<1 细菌 (CFU/ml)),无热原(<0.03 内毒素 (EU/ml)) , 无 RNase (< 0.01 ng/mL) 和无 DNase (< 4 pg/µL)

描述 HEPES

Synonyms: 2-[4-(2-Hydroxyethyl)-1-piperazinyl]ethanesulfonic acid or 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid or N-(2-Hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid)
C8H18N2O4S
Mr 238.31
CAS Number [7365-45-9]
EC Number 230-907-9
Beilstein Registry Number 883043
Merck 14,4654
RTECS TL6809000
MDL Number MFCD00006158
PubChem Substance ID 24895616
Purity ≥ 99.5%
pKa 7.5 at 25°C

Useful pH range of HEPES buffer 6.8 – 8.2

别名:2-[4-(2-Hydroxyethyl)-1-piperazine]ethanesulfonic acid or 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid or N-(2-Hydroxyethyl)piperazine-N’-(2-ethanesulfonic 酸)
C8H18N2O4S
238.31 先生
CAS 编号 [7365-45-9]
欧盟编号 230-907-9
贝尔斯坦注册号 883043
默克 14,4654
RTECS TL6809000
MDL 编号 MFCD00006158
PubChem 物质 ID 24895616
纯度≥99.5%
pKa 7.5 在 25°C

HEPES 缓冲液的有用 pH 范围 6.8 – 8.2

Titrate HR2-585 to the desired pH between 6.8 – 8.2 using NaOH
HR2-585 Measured pH Range: 5.4 – 5.5 at 25°C
HR2-585 Measured Conductivity Range: 160.1 – 236.9 μS/cm at 25°C
HR2-585 Measured Refractive Index Range: 1.37093 – 1.37131 at 20°C

HR2-785 is titrated to pH 7.0 using NaOH
HR2-785 Measured Conductivity Range: 5.8 – 7.0 mS/cm at 25°C
HR2-785 Measured Refractive Index Range: 1.37133 – 1.37176 at 20°C

HR2-729 is titrated to pH 7.5 using NaOH
HR2-729 Measured Conductivity Range: 11.6 – 13.6 mS/cm at 25°C
HR2-729 Measured Refractive Index Range: 1.37177 – 1.37290 at 20°C

Insoluble Matter 0.01% max
DNase None Detected
RNase None Detected
Protease None Detected
Heavy Metals 1 ppm max
As 5 ppm max
Cu 5 ppm max
Fe 5 ppm max
Pb 5 ppm max
SO4 0.005% max

HEPES Buffer
CAT NO

HR2-585

NAME

1.0 M HEPES

DESCRIPTION

100 mL

PRICE

$113.00

CAT NO

HR2-785

NAME

1.0 M HEPES pH 7.0

DESCRIPTION

100 mL

PRICE

$113.00

CAT NO

HR2-729

NAME

1.0 M HEPES pH 7.5

DESCRIPTION

100 mL

PRICE

$113.00

相关项目

  • Sodium hydroxide
  • StockOptions Hepes Buffer Kit
  • Individual StockOptions HEPES Reagents
  • 氢氧化钠
    StockOptions Hepes 缓冲液套件
    个别股票期权 HEPES 试剂

参考

1. Crystallization and preliminary X-ray crystallographic studies of native elastase from North Atlantic salmon (Salmo salar). Berglund, GI; Snalas, AO; Hansen, LK. Acta Crystallogr D 51, 393- 394, 1995.

1. 来自北大西洋鲑鱼 (Salmo salar) 的天然弹性蛋白酶的结晶和初步 X 射线晶体学研究。 伯格伦德,GI; 斯纳拉斯,AO; 汉森,LK。 晶体学学报 D 51, 393-394, 1995。

Hampton蛋白结晶试剂盒HEPES sodium Buffer

上海金畔生物代理Hampton research品牌蛋白结晶试剂耗材工具等,我们将竭诚为您服务,欢迎访问Hampton research官网或者咨询我们获取更多相关Hampton research品牌产品信息。

Products > Optimize Reagents > Optimize – Buffers > HEPES sodium Buffer

HEPES sodium Buffer

应用

  • Crystallization grade HEPES sodium buffer for formulating screens or for optimization
  • 用于配制筛选或优化的结晶级 HEPES 钠缓冲液

特征

  • Sterile filtered
  • Formulated in Type 1+ ultrapure water: 18.2 megaohm-cm resistivity at 25°C, < 5 ppb Total Organic Carbon, bacteria free (<1 Bacteria (CFU/ml)), pyrogen free (<0.03 Endotoxin (EU/ml)), RNase-free (< 0.01 ng/mL) and DNase-free (< 4 pg/µL)
  • 无菌过滤
    在 1+ 型超纯水中配制:25°C 时电阻率为 18.2 兆欧厘米,总有机碳 < 5 ppb,无细菌(<1 细菌 (CFU/ml)),无热原(<0.03 内毒素 (EU/ml)) , 无 RNase (< 0.01 ng/mL) 和无 DNase (< 4 pg/µL)

描述HEPES sodium

Synonyms: HEPES sodium salt, or 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid sodium salt, or N-(2-hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid) sodium salt
C8H17N2NaO4S
Mr 260.29
CAS [75277-39-3]
EC Number 278-169-7
MDL Number MFCD00036463
PubChem Substance ID 24895780
pKa 7.5 at 25°C
Useful pH Range of HEPES sodium: 6.6 – 8.2

别名:HEPES钠盐,或4-(2-羟乙基)哌嗪-1-乙磺酸钠盐,或N-(2-羟乙基)哌嗪-N’-(2-乙磺酸)钠盐
C8H17N2NaO4S
260.29 先生
CAS [75277-39-3]
欧盟编号 278-169-7
MDL 编号 MFCD00036463
PubChem 物质 ID 24895780
pKa 7.5 在 25°C
HEPES钠的有用pH范围:6.6 – 8.2

HR2-733 is titrated to pH 7.5 using HCl
HR2-733 measured Conductivity range: 41.7 – 43.4 mS/cm at 25°C
HR2-733 measured Refractive Index range: 1.37577 – 1.37766 at 20°C

HR2-577 is the free base of HEPES sodium and is to be titrated to the desired pH using HCl
HR2-577 measured pH Range: 10.2 – 12.1 at 25°C
HR2-577 measured Conductivity range: 25.9 – 27.2 mS/cm at 25°C
HR2-577 measured Refractive Index range: 1.37097 – 1.37298 at 20°C

HR2-931-01 – 1.0 M HEPES sodium pH 6.8 is a Custom Shop reagent and is used to reproduce and optimize Crystallization Reagents for use with the Silver Bullets kit.

使用 HCl 将 HR2-733 滴定至 pH 7.5
HR2-733 测量的电导率范围:25°C 时 41.7 – 43.4 mS/cm
HR2-733 测量的折射率范围:20°C 时为 1.37577 – 1.37766

HR2-577 是 HEPES 钠的游离碱,使用 HCl 滴定至所需的 pH 值
HR2-577 测量的 pH 范围:25°C 时为 10.2 – 12.1
HR2-577 测量的电导率范围:25.9 – 27.2 mS/cm 在 25°C
HR2-577 测量的折射率范围:20°C 时为 1.37097 – 1.37298

HR2-931-01 – 1.0 M HEPES 钠 pH 6.8 是 Custom Shop 试剂,用于复制和优化与 Silver Bullets 试剂盒配合使用的结晶试剂。

HEPES sodium Buffer
CAT NO

HR2-577

NAME

1.0 M HEPES sodium

DESCRIPTION

100 mL

PRICE

$133.00

CAT NO

HR2-733

NAME

1.0 M HEPES sodium pH 7.5

DESCRIPTION

100 mL

PRICE

$133.00

相关项目

  • Hydrochloric acid
  • StockOptions Sodium HEPES Buffer Kit
  • Individual StockOptions Sodium HEPES Reagents
  • 盐酸
    StockOptions HEPES 钠缓冲液套件
    个别股票期权 HEPES 钠试剂

参考

1. Crystallization and preliminary X-ray characterization of GM2-activator protein. C. S. Wright and S.-C. Li. Acta Cryst. (1997). D53, 211-212.

1. GM2 激活蛋白的结晶和初步 X 射线表征。 C. S. 赖特和 S.-C。 李。 晶体学报。 (1997)。 D53,211-212。

Hampton蛋白结晶试剂盒Imidazole Buffer/HR2-573/HR2-819

上海金畔生物代理Hampton research品牌蛋白结晶试剂耗材工具等,我们将竭诚为您服务,欢迎访问Hampton research官网或者咨询我们获取更多相关Hampton research品牌产品信息。

Products > Optimize Reagents > Optimize – Buffers > Imidazole Buffer

Imidazole Buffer

应用

  • Crystallization grade Imidazole for formulating screens or for optimization
  • 用于配制筛选或优化的结晶级咪唑

特征

  • Sterile filtered
  • Formulated in Type 1+ ultrapure water: 18.2 megaohm-cm resistivity at 25°C, < 5 ppb Total Organic Carbon, bacteria free (<1 Bacteria (CFU/ml)), pyrogen free (<0.03 Endotoxin (EU/ml)), RNase-free (< 0.01 ng/mL) and DNase-free (< 4 pg/µL)
  • 无菌过滤
    在 1+ 型超纯水中配制:25°C 时电阻率为 18.2 兆欧厘米,总有机碳 < 5 ppb,无细菌(<1 细菌 (CFU/ml)),无热原(<0.03 内毒素 (EU/ml)) , 无 RNase (< 0.01 ng/mL) 和无 DNase (< 4 pg/µL)

描述 Imidazole

Synonyms: 1,3-Diaza-2,4-cyclopentadiene or Glyoxaline
C3H4N2
Mr 68.08
CAS Number [288-32-4]
EC Number 206-019-2
Beilstein Registry Number 103853
Merck 14,4912
RTECS NI3325000
MDL Number MFCD00005183
PubChem Substance ID 24880372
Purity ≥ 99.5%
UN Number 2923 8/PG 3

pKa = 6.95
The useful pH range of an Imidazole can be 6.2 – 7.8

HR2-819 is titrated to pH 7.0 using HCl
HR2-819 Measured Conductivity Range: 45.4 – 50.4 mS/cm at 25°C
HR2-819 Measured Refractive Index Range: 1.34836 – 1.34904 at 20°C

Titrate HR2-573 to the desired pH using HCl
HR2-573 Measured pH Range: 10.5 – 10.7 at 25°C
HR2-573 Measured Conductivity Range: 71.1 – 101.5 µS/cm at 25°C
HR2-573 Measured Refractive Index Range: 1.34420 – 1.34440 at 20°C

同义词:1,3-Diaza-2,4-cyclopentadiene 或 Glyoxaline
C3H4N2
68.08 先生
CAS 编号 [288-32-4]
欧盟编号 206-019-2
贝尔斯坦注册号 103853
默克 14,4912
RTECS NI3325000
MDL 编号 MFCD00005183
PubChem 物质 ID 24880372
纯度≥99.5%
联合国编号 2923 8/PG 3

pKa = 6.95
咪唑的有用 pH 范围可以是 6.2 – 7.8

HR2-819 使用 HCl 滴定至 pH 7.0
HR2-819 测得的电导率范围:25°C 时为 45.4 – 50.4 mS/cm
HR2-819 测量的折射率范围:20°C 时为 1.34836 – 1.34904

使用 HCl 将 HR2-573 滴定至所需的 pH 值
HR2-573 测得的 pH 范围:25°C 时 10.5 – 10.7
HR2-573 测得的电导率范围:25°C 时为 71.1 – 101.5 µS/cm
HR2-573 测量的折射率范围:20°C 时为 1.34420 – 1.34440

Ca  ≤0.001%
Cd  ≤0.0005%
Cl   ≤0.005%
Co  ≤0.0005%
Cr  ≤0.0005%
Cu  ≤0.0005%
Fe  ≤0.0005%
K   ≤0.005%
Mg ≤0.0005%
Na ≤0.005%
Ni  ≤0.0005%
Pb  ≤0.0005%
SO4 ≤0.005%
Zn  ≤0.0005%

Imidazole Buffer
CAT NO

HR2-573

NAME

1.0 M Imidazole

DESCRIPTION

100 mL

PRICE

$93.00

CAT NO

HR2-819

NAME

1.0 M Imidazole pH 7.0

DESCRIPTION

100 mL

PRICE

$111.00

相关项目

  • Hydrochloric acid
  • Individual StockOptions Imidazole Reagents
  • StockOptions Imidazole Kit
  • 盐酸
    个别股票期权 咪唑试剂
    StockOptions 咪唑试剂盒

参考

1. Structure of apo acyl carrier protein and a proposal to engineer protein crystallization through metal ions. X. Qiu and C. A. Janson. Acta Cryst. (2004). D60, 1545-1554 [doi:10.1107/S0907444904015422].

2. Protein crystallization by surface entropy reduction: optimization of the SER strategy. D. R. Cooper, T. Boczek, K. Grelewska, M. Pinkowska, M. Sikorska, M. Zawadzki and Z. Derewenda. Acta Cryst. (2007). D63, 636-645 [doi:10.1107/S0907444907010931].

1. apo 酰基载体蛋白的结构和通过金属离子设计蛋白质结晶的建议。 X. 邱和 C. A. Janson。 晶体学报。 (2004 年)。 D60, 1545-1554 [doi:10.1107/S0907444904015422]。

2. 表面熵减少的蛋白质结晶:SER 策略的优化。 D. R. Cooper、T. Boczek、K. Grelewska、M. Pinkowska、M. Sikorska、M. Zawadzki 和 Z. Derewenda。 晶体学报。 (2007 年)。 D63, 636-645 [doi:10.1107/S0907444907010931]。

MES monohydrate Buffer/HR2-587 0.5 M MES monohydrate/HR2-787 1.0 M MES monohydrate pH 6.5

上海金畔生物代理Hampton research品牌蛋白结晶试剂耗材工具等,我们将竭诚为您服务,欢迎访问Hampton research官网或者咨询我们获取更多相关Hampton research品牌产品信息。

Products > Optimize Reagents > Optimize – Buffers > MES monohydrate Buffer

MES monohydrate Buffer

CAT NO

HR2-587

NAME

 0.5 M MES monohydrate

DESCRIPTION

100 mL

PRICE

$141.00

CAT NO

HR2-787

NAME

 1.0 M MES monohydrate pH 6.5

DESCRIPTION

100 mL

PRICE

$141.00

MES monohydrate Buffer

应用

  • Crystallization grade MES monohydrate for formulating screens or for optimization
  • 用于配制筛选或优化的结晶级 MES 一水合物

特征

  • Sterile filtered
  • Formulated in Type 1+ ultrapure water: 18.2 megaohm-cm resistivity at 25°C, < 5 ppb Total Organic Carbon, bacteria free (<1 Bacteria (CFU/ml)), pyrogen free (<0.03 Endotoxin (EU/ml)), RNase-free (< 0.01 ng/mL) and DNase-free (< 4 pg/µL)
  • 无菌过滤
    在 1+ 型超纯水中配制:25°C 时电阻率为 18.2 兆欧厘米,总有机碳 < 5 ppb,无细菌(<1 细菌 (CFU/ml)),无热原(<0.03 内毒素 (EU/ml)) , 无 RNase (< 0.01 ng/mL) 和无 DNase (< 4 pg/µL)

描述 MES monohydrate

Synonyms: MES or 2-(N-morpholino)ethanesulfonic acid or 4-morpholineethanesulfonic acid monohydrate
C6H13NO4S • H2O
Mr 213.25
CAS Number [145224-94-8]
EC Number 224-632-3
Beilstein Registry Number 329824236
RTECS QE3479500
MDL Number MFCD00149409
PubChem Substance ID 24885996
Purity ≥ 99.0%
pKa 6.1 at 25°C

Solutions are stable at 2-8°C for months. Autoclaving is not recommended for any sulfonic acid buffer. When MES solutions are autoclaved, they turn yellow (although pH does not change measurably). The identity of the yellow breakdown product is unknown. When MES solutions are stored at room temperature, they can turn yellow within six months.

Useful pH range of MES 5.2 – 7.1

Titrate HR2-587 to the desired pH using NaOH
HR2-587 Measured pH Range: 3.2 – 3.4 at 25°C
HR2-587 Measured Conductivity Range: 166.4 – 2440 µS/cm at 25°C
HR2-587 Measured Refractive Index Range: 1.34655 – 1.34731 at 20°C

HR2-787 has been titrated to pH 6.5 using NaOH
HR2-787 Measured Conductivity Range: 19.2 – 25.6 mS/cm at 25°C
HR2-787 Measured Refractive Index Range: 1.36113 – 1.36251 at 20°C

HR2-943-07 – MES monohydrate pH 5.8 – 1.0 M solution is a Custom Shop reagent and is used to reproduce and optimize Crystallization Reagents for use with the Silver Bullets kit.

同义词:MES或2-(N-吗啉代)乙磺酸或4-吗啉乙磺酸一水合物
C6H13NO4S • H2O
213.25 先生
CAS 编号 [145224-94-8]
欧盟编号 224-632-3
贝尔斯坦注册号 329824236
RTECS QE3479500
MDL 编号 MFCD00149409
PubChem 物质 ID 24885996
纯度≥99.0%
pKa 6.1 在 25°C

溶液在 2-8°C 下可稳定数月。不建议对任何磺酸缓冲液进行高压灭菌。当 MES 溶液经过高压灭菌时,它们会变黄(尽管 pH 值不会发生可测量的变化)。黄色分解产物的身份不明。当 MES 溶液在室温下储存时,它们会在六个月内变黄。

MES 5.2 – 7.1 的有用 pH 范围

使用 NaOH 将 HR2-587 滴定至所需的 pH 值
HR2-587 测得的 pH 范围:25°C 时为 3.2 – 3.4
HR2-587 测得的电导率范围:25°C 时为 166.4 – 2440 µS/cm
HR2-587 测量的折射率范围:20°C 时为 1.34655 – 1.34731

HR2-787 已使用 NaOH 滴定至 pH 6.5
HR2-787 测量的电导率范围:25°C 时为 19.2 – 25.6 mS/cm
HR2-787 测量的折射率范围:20°C 时为 1.36113 – 1.36251

HR2-943-07 – MES 一水合物 pH 5.8 – 1.0 M 溶液是 Custom Shop 试剂,用于重现和优化用于 Silver Bullets 试剂盒的结晶试剂。

Impurities:
Endotoxin ≤ 50 EU/g
Yeast and Mold ≤ 100 CFU/g
Bioburden ≤ 100 CFU/g
Al ≤ 5.0 ppm
As ≤ 3.0 ppm
Ba ≤ 5.0 ppm
Bi ≤ 5.0 ppm
Ca ≤ 20.0 ppm
Cd ≤ 5.0 ppm
Co ≤ 5.0 ppm
Cr ≤ 5.0 ppm
Cu ≤ 5.0 ppm
Fe ≤ 5.0 ppm
Li ≤ 5.0 ppm
Mg ≤ 5.0 ppm
Mn ≤ 5.0 ppm
Mo ≤ 5.0 ppm
Na ≤ 20.0 ppm
Ni ≤ 5.0 ppm
Pb ≤ 5.0 ppm
Sb ≤ 5.0 ppm
Zn ≤ 5.0 ppm

相关项目

  • Sodium hydroxide
  • StockOptions MES Buffer Kit
  • Individual StockOptions MES Reagents
  • 氢氧化钠
    StockOptions MES 缓冲套件
    个别股票期权 MES 试剂

参考

1. Crystal structures of mutant Pseudomonas aeruginosa p-hydroxybenzoate hydroxylases: the Tyr201Phe, Tyr385Phe, and Asn300Asp variants. Lah, MS; Palfey, BA; Schreuder, HA; Ludwig, ML. Biochemistry 33, 1555- 1564, 1994.

1. 突变铜绿假单胞菌对羟基苯甲酸羟化酶的晶体结构:Tyr201Phe、Tyr385Phe 和 Asn300Asp 变体。 拉,女士; 帕尔菲,文学士; 施罗德,HA; 路德维希,ML。 生物化学 33, 1555-1564, 1994。

Hampton蛋白结晶试剂盒Perfluoropolyether Cryo Oil/HR2-814

上海金畔生物代理Hampton research品牌蛋白结晶试剂耗材工具等,我们将竭诚为您服务,欢迎访问Hampton research官网或者咨询我们获取更多相关Hampton research品牌产品信息。

Products > Optimize Reagents > Optimize – Cryoprotectants > Perfluoropolyether Cryo Oil

Perfluoropolyether Cryo Oil全氟聚醚冷冻油

Perfluoropolyether Cryo Oil

CAT NO

HR2-814

NAME

Perfluoropolyether Cryo Oil

DESCRIPTION

1 mL

PRICE

$33.00

应用

  • Oil based cryoprotectant
  • 油基防冻剂

特征

  • Perfluoropolyether cryo oil
  • Low viscosity
  • Low surface tension
  • Cryoprotectant for soluble and membrane protein crystals
  • 全氟聚醚冷冻油
    低粘度
    低表面张力
    可溶性和膜蛋白晶体的冷冻保护剂

描述

Used during cryocrystallography to displace and reduce the amount of water (mother liquor, reagent) on the crystal after the crystal is mounted in a cryoloop. Coating the crystal with oil can minimize evaporation from the crystal and reduce exposure and slow diffusion of air (oxygen) to the crystal.

Perfluoropolyether Cryo Oil offers low viscosity, extremely low vapor pressure, low surface tension, excellent chemical inertness and excellent thermal stability.

Dip the mounted crystal into the oil to displace surface water. Or add a small amount of Perfluoropolyether to the crystallization drop before mounting the crystal. After adding the Perfluoropolyether, mount the crystal using a Mounted Cryoloop. Withdraw the mounted crystal from the drop and the Perfluoropolyether will coat the mounted crystal. Cryogenically cool the mounted crystal.

在晶体安装在低温回路中后,在低温晶体学期间用于置换和减少晶体上的水(母液、试剂)量。 用油涂抹晶体可以最大限度地减少晶体的蒸发并减少空气(氧气)向晶体的暴露和缓慢扩散。

全氟聚醚冷冻油具有低粘度、极低蒸气压、低表面张力、优异的化学惰性和优异的热稳定性。

将安装的晶体浸入油中以置换表面水。 或者在安装晶体之前在结晶液滴中加入少量的全氟聚醚。 添加全氟聚醚后,使用 Mounted Cryoloop 安装晶体。 从液滴中取出已镶嵌的晶体,全氟聚醚将覆盖已镶嵌的晶体。 低温冷却安装的晶体。

相关项目

  • CryoPro

参考

1. Structure of the ‘open form’ of Aspergillus nidulans 3-dehydroquinate synthase at 1.7 Å resolution. C.E. Nichols, A.R. Hawkins and D.K. Stammersa. Acta Crystallographic Section D, Volume 60, Part 5, Pages 971-973, May 2004.

2. H. Hope, Annu. Rev. Biophys. Chem. 1990 19:107-126.
1. 构巢曲霉 3-脱氢喹酸合酶“开放形式”的结构,分辨率为 1.7 Å。 C.E.尼科尔斯,A.R. 霍金斯和 D.K. 斯塔默萨。 晶体学报 D 部分,第 60 卷,第 5 部分,第 971-973 页,2004 年 5 月。

2. H.希望,安努。 牧师生物物理学。 化学。 1990 年 19:107-126。

Hampton蛋白结晶试剂盒Sodium cacodylate trihydrate Buffer/HR2-575/HR2-737

上海金畔生物代理Hampton research品牌蛋白结晶试剂耗材工具等,我们将竭诚为您服务,欢迎访问Hampton research官网或者咨询我们获取更多相关Hampton research品牌产品信息。

Products > Optimize Reagents > Optimize – Buffers > Sodium cacodylate trihydrate Buffer

Sodium cacodylate trihydrate Buffer二甲胂酸钠三水合物

Sodium cacodylate trihydrate Buffer
CAT NO

HR2-575

NAME

1.0 M Sodium cacodylate trihydrate

DESCRIPTION

100 mL

PRICE

$244.00

CAT NO

HR2-737

NAME

1.0 M Sodium cacodylate trihydrate pH 6.5

DESCRIPTION

100 mL

PRICE

$244.00

应用

  • Crystallization grade Sodium cacodylate trihydrate buffer for formulating screens or for optimization
  • 结晶级二甲胂酸钠三水合物缓冲液,用于配制筛选或优化

特征

  • Sterile filtered
  • Formulated in Type 1+ ultrapure water: 18.2 megaohm-cm resistivity at 25°C, < 5 ppb Total Organic Carbon, bacteria free (<1 Bacteria (CFU/ml)), pyrogen free (<0.03 Endotoxin (EU/ml)), RNase-free (< 0.01 ng/mL) and DNase-free (< 4 pg/µL)
  • 无菌过滤
    在 1+ 型超纯水中配制:25°C 时电阻率为 18.2 兆欧厘米,总有机碳 < 5 ppb,无细菌(<1 细菌 (CFU/ml)),无热原(<0.03 内毒素 (EU/ml)) , 无 RNase (< 0.01 ng/mL) 和无 DNase (< 4 pg/µL)

描述Sodium cacodylate trihydrate

Synonyms: Cacodylic acid sodium salt trihydrate or Dimethylarsinic acid sodium salt or Dimethylarsonic acid sodium salt
C2H6AsNaO2 • 3H2O
(CH3)2AsO2Na • 3H2O
Mr 214.03
CAS Number [6131-99-3]
EC Number 204-708-2
Beilstein Registry Number 3702348
Merck 14,8595
RTECS CH7890000
MDL Number MFCD00149079
PubChem Substance ID 24892242
Purity ≥ 98.0%
UN Number UN 1688 6.1/PG 2
pKa 6.3 at 25°C

Useful pH Range of a Sodium cacodylate trihydrate buffer is 5.0 – 7.4

HR2-737 is titrated to pH 6.5 using HCl
HR2-737 Measured Conductivity Range: 43.4 – 47.1 mS/cm at 25°C
HR2-737 Measured Refractive Index Range: 1.35633 – 1.35711 at 20°C

Titrate HR2-575 to the desired pH using HCl
HR2-575 Measured pH Range: 8.4 – 8.5 at 25°C
HR2-575 Measured Conductivity Range: 33.7 – 36.5 mS/cm at 25°C
HR2-575 Measured Refractive Index Range: 1.35556 – 1.35635 at 20°C

别名:二甲胂酸钠盐三水合物或二甲基胂酸钠盐或二甲基胂酸钠盐
C2H6AsNaO2 • 3H2O
(CH3)2AsO2Na • 3H2O
214.03 先生
CAS 编号 [6131-99-3]
欧盟编号 204-708-2
贝尔斯坦注册号 3702348
默克 14,8595
RTECS CH7890000
MDL 编号 MFCD00149079
PubChem 物质 ID 24892242
纯度≥98.0%
联合国编号 UN 1688 6.1/PG 2
pKa 6.3 在 25°C

二甲胂酸钠三水合物缓冲液的有用 pH 范围为 5.0 – 7.4

使用 HCl 将 HR2-737 滴定至 pH 6.5
HR2-737 测得的电导率范围:25°C 时 43.4 – 47.1 mS/cm
HR2-737 测量的折射率范围:20°C 时为 1.35633 – 1.35711

使用 HCl 将 HR2-575 滴定至所需的 pH 值
HR2-575 测量的 pH 范围:25°C 时 8.4 – 8.5
HR2-575 测得的电导率范围:25°C 时 33.7 – 36.5 mS/cm
HR2-575 测量的折射率范围:20°C 时为 1.35556 – 1.35635

相关项目

  • Hydrochloric acid
  • StockOptions Sodium Cacodylate Buffer Kit
  • Individual StockOptions Sodium Cacodylate Reagents
  • 盐酸
    StockOptions 二甲胂酸钠缓冲液试剂盒
    个人股票期权二甲胂酸钠试剂

参考

1. The high-resolution crystal structure of a parallel-stranded guanine tetraplex. Laughlan, G; Murchie, AI; Norman, DG; Moore, MH; Moody, PC; Lilley, DM; Luisi, B. Science 265, 520- 524, 1994.

2. Get phases from arsenic anomalous scattering: de novo SAD phasing of two protein structures crystallized in cacodylate buffer. Liu X, Zhang H, Wang XJ, Li LF, Su XD. PLoS One. 2011;6(9):e24227. Epub 2011 Sep 2.

1. 平行链鸟嘌呤四链体的高分辨率晶体结构。 劳克兰,G; 默奇,人工智能; 诺曼,总干事; 摩尔,MH; 穆迪,个人电脑; 莉莉,DM; Luisi, B. Science 265, 520-524, 1994。

2. 从砷异常散射中获取相位:在二甲胂酸盐缓冲液中结晶的两种蛋白质结构的从头 SAD 相位。 刘 X,张 H,王 XJ,李 LF,苏 XD。 公共科学图书馆一号。 2011;6(9):e24227。 Epub 2011 年 9 月 2 日。

Hampton蛋白结晶试剂盒Santovac Cryo Oil/HR2-861

上海金畔生物代理Hampton research品牌蛋白结晶试剂耗材工具等,我们将竭诚为您服务,欢迎访问Hampton research官网或者咨询我们获取更多相关Hampton research品牌产品信息。

Products > Optimize Reagents > Optimize – Cryoprotectants > Santovac Cryo Oil

Santovac Cryo Oil

Santovac Cryo Oil
CAT NO

HR2-861

NAME

Santovac Cryo Oil

DESCRIPTION

1 mL

PRICE

$26.00

应用

  • Oil based cryoprotectant
  • 油基防冻剂

特征

  • Low viscosity
  • Low surface tension
  • Cryoprotectant for soluble and membrane protein crystals
  • Not miscible with most solvents
  • Non toxic, non penetrating cryoprotectant
  • 低粘度
    低表面张力
    可溶性和膜蛋白晶体的冷冻保护剂
    不与大多数溶剂混溶
    无毒、非渗透性冷冻保护剂

描述

Used during cryocrystallography to displace and reduce the amount of water (mother liquor, reagent) on the crystal after the crystal is mounted in a cryoloop. Coating the crystal with oil can minimize evaporation from the crystal and reduce exposure and slow diffusion of air (oxygen) to the crystal.

Santovac Cryo Oil offers low viscosity, incredibly low vapor pressure, low surface tension, excellent chemical inertness and excellent thermal stability.

Dip the mounted crystal into the oil to displace surface water. Or add a small amount of Santovac to the crystallization drop before mounting the crystal. After adding the Santovac, mount the crystal using a Mounted Cryoloop. Withdraw the mounted crystal from the drop and the Santovac will coat the mounted crystal. Cryogenically cool the mounted crystal.

Santovac (Santovac 5) is a five ring polyphenyl ether (PPE) with very low vapor pressure and low reactivity. The oil is highly resistant to oxidation. The only elements in the pure polyphenyl ether are oxygen, hydrogen and carbon.

The fluid is chemically stable, non-corrosive, safe and non-toxic at normal operating temperatures.

Santovac is not miscible with water, paraffin oil, silicon oil, alkanes, or Parabar 10312 (Paratone). Santovac is miscible with acetone. Shelf life 5 years.

Santovac® is a trademark of Santovac® Fluids.

在晶体安装在低温回路中后,在低温晶体学期间用于置换和减少晶体上的水(母液、试剂)量。用油涂抹晶体可以最大限度地减少晶体的蒸发并减少空气(氧气)向晶体的暴露和缓慢扩散。

Santovac Cryo Oil 具有低粘度、极低的蒸气压、低表面张力、出色的化学惰性和出色的热稳定性。

将安装的晶体浸入油中以置换表面水。或者在安装晶体之前将少量的 Santovac 添加到结晶液滴中。添加 Santovac 后,使用 Mounted Cryoloop 安装晶体。从水滴中取出已镶嵌的水晶,Santovac 将覆盖已镶嵌的水晶。低温冷却安装的晶体。

Santovac (Santovac 5) 是一种五环聚苯醚 (PPE),具有极低的蒸气压和低反应性。该油具有很强的抗氧化性。纯聚苯醚中唯一的元素是氧、氢和碳。

该流体在正常工作温度下化学性质稳定、无腐蚀性、安全无毒。

Santovac 与水、石蜡油、硅油、烷烃或 Parabar 10312 (Paratone) 不混溶。 Santovac 可与丙酮混溶。保质期5年。

Santovac® 是 Santovac® Fluids 的商标。

Santovac Cryo Oil

支持材料

HR2-861 Santovac Cryo Oil User Guide HR2-861 Santovac Cryo Oil SDS

相关项目

  • CryoPro

参考

1. Structure of the ‘open’ form of Aspergillus nidulans 3-dehydroquinate synthase at 1.7 Å resolution from crystal grown following enzyme turnover. C.E. Nichols, A.R. Hawkins and D.K. Stammersa. Acta Crystallographic Section D, Volume 60, Part 5, Pages 971-973, May 2004.

2. Crystal Structure of the Caspase Activator Human Granzyme B, a Proteinase Highly Specific for an Asp-P1 Residue. E. Estebanez-Perpina et al. Biol. Chem., Vol. 381, pp. 1203-1214, December 2000.

1. 构巢曲霉 3-脱氢喹酸合酶“开放”形式的结构,分辨率为 1.7 Å,来自酶转换后生长的晶体。 C.E.尼科尔斯,A.R. 霍金斯和 D.K. 斯塔默萨。 晶体学报 D 部分,第 60 卷,第 5 部分,第 971-973 页,2004 年 5 月。

2. Caspase 激活剂人粒酶 B 的晶体结构,一种对 Asp-P1 残基具有高度特异性的蛋白酶。 E. Estebanez-Perpina 等人。 生物学。 化学,卷。 381,第 1203-1214 页,2000 年 12 月。

Hampton蛋白结晶试剂盒Sodium citrate tribasic dihydrate Buffer/HR2-571/HR2-735

上海金畔生物代理Hampton research品牌蛋白结晶试剂耗材工具等,我们将竭诚为您服务,欢迎访问Hampton research官网或者咨询我们获取更多相关Hampton research品牌产品信息。

Products > Optimize Reagents > Optimize – Buffers > Sodium citrate tribasic dihydrate Buffer

Sodium citrate tribasic dihydrate Buffer

Sodium citrate tribasic dihydrate Buffer
CAT NO

HR2-571

NAME

1.0 M Sodium citrate tribasic dihydrate

DESCRIPTION

100 mL

PRICE

$56.00

CAT NO

HR2-735

NAME

1.0 M Sodium citrate tribasic dihydrate pH 5.6

DESCRIPTION

100 mL

PRICE

$56.00

支持材料

Sodium citrate tribasic dihydrate Buffer HR2-571 Sodium citrate tribasic dihydrate SDSSodium citrate tribasic dihydrate Buffer HR2-735 Sodium citrate tribasic dihydrate pH 5.6 SDSSodium citrate tribasic dihydrate Buffer Titration Table

应用

  • Crystallization grade Sodium citrate tribasic dihydrate buffer for formulating screens or for optimization
  • 结晶级柠檬酸钠三水合物缓冲液,用于配制筛选或优化

特征

  • Sterile filtered
  • Formulated in Type 1+ ultrapure water: 18.2 megaohm-cm resistivity at 25°C, < 5 ppb Total Organic Carbon, bacteria free (<1 Bacteria (CFU/ml)), pyrogen free (<0.03 Endotoxin (EU/ml)), RNase-free (< 0.01 ng/mL) and DNase-free (< 4 pg/µL)
  • 无菌过滤
    在 1+ 型超纯水中配制:25°C 时电阻率为 18.2 兆欧厘米,总有机碳 < 5 ppb,无细菌(<1 细菌 (CFU/ml)),无热原(<0.03 内毒素 (EU/ml)) , 无 RNase (< 0.01 ng/mL) 和无 DNase (< 4 pg/µL)

描述

Sodium citrate tribasic dihydrate

Synonyms: Citric acid trisodium salt dihydrate or Trisodium citrate dihydrate
C6H5Na3O7 • 2H2O
HOC(COONa)(CH2COONa)2 • 2H2O
Mr 294.10
CAS Number [6132-04-3]
EC Number 200-675-3
Merck 14,8602
Beilstein Registry Number 6104939
MDL Number MFCD00150031
Purity ≥ 99.0%

Useful pH range of a Sodium citrate tribasic dihydrate buffer: 2.2 – 6.5

Titrate HR2-571 to the desired pH using HCl
HR2-571 Measured pH Range: 8.1 – 9.4 at 25°C
HR2-571 Measured Conductivity Range: 60.0 – 69.8 mS/cm at 25°C
HR2-571 Measured Refractive Index Range: 1.37345 – 1.37370 at 20°C

HR2-735 is titrated to pH 5.6 using HCl
HR2-735 Measured Conductivity Range: 67.4 – 78.5 mS/cm at 25°C
HR2-735 Measured Refractive Index Range: 1.37400 – 1.37502 at 20°C

别名:柠檬酸三钠盐二水合物或柠檬酸三钠二水合物
C6H5Na3O7 • 2H2O
HOC(COONa)(CH2COONa)2 • 2H2O
294.10 先生
CAS 编号 [6132-04-3]
欧盟编号 200-675-3
默克 14,8602
贝尔斯坦注册号 6104939
MDL 编号 MFCD00150031
纯度≥99.0%

柠檬酸钠三水合物缓冲液的有用 pH 范围:2.2 – 6.5

使用 HCl 将 HR2-571 滴定至所需的 pH 值
HR2-571 测量的 pH 范围:25°C 时 8.1 – 9.4
HR2-571 测量的电导率范围:25°C 时为 60.0 – 69.8 mS/cm
HR2-571 测量的折射率范围:20°C 时为 1.37345 – 1.37370

使用 HCl 将 HR2-735 滴定至 pH 5.6
HR2-735 测得的电导率范围:25°C 时为 67.4 – 78.5 mS/cm
HR2-735 测量的折射率范围:20°C 时为 1.37400 – 1.37502

Al  ≤0.0005%
As ≤0.00001%
Ba ≤0.0005%
Bi  ≤0.0005%
Ca ≤0.005%
Cd ≤0.0005%
Cl  ≤0.001%
Co ≤0.0005%
Cr ≤0.0005%
Cu ≤0.0005%
Fe ≤0.0005%
K   ≤0.01%
Li   ≤0.0005%
Mg ≤0.0005%
Mn ≤0.0005%
Mo ≤0.0005%
NH4+ ≤0.001%
Ni  ≤0.0005%
Pb ≤0.0005%
SO4 ≤0.005%
Zn ≤0.0005%

Sodium citrate tribasic dihydrate

相关项目

  • Hydrochloric acid
  • StockOptions Sodium Citrate Buffer Kit
  • Individual StockOptions Sodium Citrate Reagents
  • 盐酸
    StockOptions 柠檬酸钠缓冲液套件
    个别股票期权柠檬酸钠试剂

参考

1. Crystallization and preliminary X-ray diffraction studies on ADP-ribosylation factor 1. Greasley, S; Jhoti, H; Fensome, AC; Cockcroft, S; Thomas, GM; Bax, B. J Mol Biol 244, 651- 653, 1994.

1. ADP-核糖基化因子的结晶和初步 X 射线衍射研究 1. Greasley, S; 乔蒂,H; 芬索姆,AC; 考克罗夫特,S; 托马斯,总经理; Bax, B. J Mol Biol 244, 651-653, 1994。

Hampton蛋白结晶试剂盒TMAO/HR2-857

上海金畔生物代理Hampton research品牌蛋白结晶试剂耗材工具等,我们将竭诚为您服务,欢迎访问Hampton research官网或者咨询我们获取更多相关Hampton research品牌产品信息。

Products > Optimize Reagents > Optimize – Cryoprotectants > TMAO

TMAO

TMAO
CAT NO

HR2-857

NAME

4.0 M TMAO

DESCRIPTION

1 mL

PRICE

$26.00

支持材料

TMAO HR2-857 4.0 M TMAO SDS

应用

  • Water soluble cryoprotectant
  • 水溶性冷冻保护剂

特征

  • A very versatile cryoprotectant for macromolecular crystals
  • Protein stabilizer
  • TMAO can be a viable alternative when conventional cryoprotectants fail
  • Low viscosity and low surface tension
  • Sterile filtered
  • Formulated in Type 1+ ultrapure water: 18.2 megaohm-cm resistivity at 25°C, < 5 ppb Total Organic Carbon, bacteria free (<1 Bacteria (CFU/ml)), pyrogen free (<0.03 Endotoxin (EU/ml)), RNase-free (< 0.01 ng/mL) and DNase-free (< 4 pg/µL)
  • 一种非常通用的大分子晶体冷冻保护剂
    蛋白质稳定剂
    当传统冷冻保护剂失效时,TMAO 可能是一种可行的替代方案
    低粘度和低表面张力
    无菌过滤
    在 1+ 型超纯水中配制:25°C 时电阻率为 18.2 兆欧厘米,总有机碳 < 5 ppb,无细菌(<1 细菌 (CFU/ml)),无热原(<0.03 内毒素 (EU/ml)) , 无 RNase (< 0.01 ng/mL) 和无 DNase (< 4 pg/µL)

描述Trimethylamine N-oxide dihydrate (TMAO)

Formulated from TMAO dihydrate in Type 1 lab water (deionized) and sterile filtered (0.22 micron)

Synonyms: TMANO, TMAO
(CH3)3NO•2H2O
C3H9NO•2H2O
Mr 111.14
CAS Number [62637-93-8]
EC Number 214-675-6
Beilstein Registry Number 4(4)144
Merck 14,9711
RTECS YH2850000
Purity ≥ 98.0%
Measured pH range: 9.2 – 10.6 at 25°C
Measured Conductivity Range: 5.6 – 96.6 µS/cm at 25°C
Measured Refractive Index Range: 1.37660 – 1.37804 at 20°C

When using TMAO as a cryoprotectant, try soaking the crystals in 4.0 M TMAO for 10 seconds and then cryo cool directly in the cryo stream.

由 1 型实验室用水(去离子)和无菌过滤(0.22 微米)中的 TMAO 二水合物配制而成

同义词:TMANO、TMAO
(CH3)3NO•2H2O
C3H9NO•2H2O
111.14 先生
CAS 编号 [62637-93-8]
欧盟编号 214-675-6
贝尔斯坦注册号 4(4)144
默克 14,9711
RTECS YH2850000
纯度≥98.0%
测得的 pH 值范围:25°C 时 9.2 – 10.6
测得的电导率范围:25°C 时 5.6 – 96.6 µS/cm
测得的折射率范围:20°C 时为 1.37660 – 1.37804

当使用 TMAO 作为冷冻保护剂时,尝试将晶体浸泡在 4.0 M TMAO 中 10 秒,然后直接在冷冻流中冷冻冷却。

相关项目

  • CryoPro

参考

1. Trimethylamine N-oxide as a versatile cryoprotective agent in macromolecular crystallography. Christoph Mueller-Dieckmann, Brice Kauffmann and Manfred S. Weiss. J. Appl. Cryst. (2011). 44, 433–436 doi:10.1107/S0021889811000045.

1. 三甲胺 N-氧化物作为大分子晶体学中的多功能冷冻保护剂。 Christoph Mueller-Dieckmann、Brice Kauffmann 和 Manfred S. Weiss。 J.应用。 水晶。 (2011)。 44, 433–436 doi:10.1107/S0021889811000045。

Hampton蛋白结晶试剂盒Tris Buffer/HR2-589/HR2-725

上海金畔生物代理Hampton research品牌蛋白结晶试剂耗材工具等,我们将竭诚为您服务,欢迎访问Hampton research官网或者咨询我们获取更多相关Hampton research品牌产品信息。

Products > Optimize Reagents > Optimize – Buffers > Tris Buffer

Tris Buffer

Tris Buffer
CAT NO

HR2-589

NAME

1.0 M Tris

DESCRIPTION

100 mL

PRICE

$60.00

CAT NO

HR2-725

NAME

1.0 M Tris pH 8.5

DESCRIPTION

100 mL

PRICE

$60.00

应用

  • Crystallization grade Tris for formulating screens or for optimization
  • 结晶级 Tris 用于配制筛选或优化

特征

  • Sterile filtered
  • Formulated in Type 1+ ultrapure water: 18.2 megaohm-cm resistivity at 25°C, < 5 ppb Total Organic Carbon, bacteria free (<1 Bacteria (CFU/ml)), pyrogen free (<0.03 Endotoxin (EU/ml)), RNase-free (< 0.01 ng/mL) and DNase-free (< 4 pg/µL)
  • 无菌过滤
    在 1+ 型超纯水中配制:25°C 时电阻率为 18.2 兆欧厘米,总有机碳 < 5 ppb,无细菌(<1 细菌 (CFU/ml)),无热原(<0.03 内毒素 (EU/ml)) , 无 RNase (< 0.01 ng/mL) 和无 DNase (< 4 pg/µL)

描述Tris

Synonyms: Trizma base or 2-Amino-2-(hydroxymethyl)-1,3-propanediol or THAM or Tris base or Tris(hydroxymethyl)aminomethane or Trometamol
C4H11NO3
NH2C(CH2OH)3
Mr 121.14
CAS Number [77-86-1]
EC Number 201-064-4
Beilstein Registry Number 741883
Merck 14,9772
RTECS TY2900000
MDL Number MFCD00004679
PubChem Substance ID 24889854
Purity 99.8 – 100.1%
pKa = 8.1 at 25°C

Useful pH range of Tris: 7.0 – 9.0

Titrate HR2-589 to the desired pH using HCl
HR2-589 Measured pH Range: 10.9 – 11.1 at 25°C
HR2-589 Measured Conductivity Range: 193.3 – 236.7 µS/cm at 25°C
HR2-589 Measured Refractive Index: 1.34991 – 1.35058 at 20°C

HR2-725 is titrated to pH 8.5 using HCl
HR2-725 Measured Conductivity Range: 18.1 – 22.7 mS/cm at 25°C
HR2-725 Measured Refractive Index: 1.35310 – 1.35369 at 20°C

同义词: Trizma 碱或 2-Amino-2-(羟甲基)-1,3-丙二醇或 THAM 或 Tris 碱或 Tris(羟甲基)氨基甲烷或氨丁三醇
C4H11NO3
NH2C(CH2OH)3
121.14 先生
CAS 编号 [77-86-1]
欧盟编号 201-064-4
贝尔斯坦注册号 741883
默克 14,9772
RTECS TY2900000
MDL 编号 MFCD00004679
PubChem 物质 ID 24889854
纯度 99.8 – 100.1%
pKa = 8.1 在 25°C

Tris 的有用 pH 值范围:7.0 – 9.0

使用 HCl 将 HR2-589 滴定至所需的 pH 值
HR2-589 测得的 pH 范围:25°C 时为 10.9 – 11.1
HR2-589 测量的电导率范围:25°C 时为 193.3 – 236.7 µS/cm
HR2-589 实测折射率:20°C 时为 1.34991 – 1.35058

使用 HCl 将 HR2-725 滴定至 pH 8.5
HR2-725 测量的电导率范围:25°C 时为 18.1 – 22.7 mS/cm
HR2-725 实测折射率:20°C 时为 1.35310 – 1.35369

Insoluble Matter 0.005% max
DNase None Detected
RNase None Detected
Protease None Detected
Heavy Metals 5 ppm max
As  ≤ 5 ppm max
Ca  ≤ 5 ppm max
Cu  ≤ 5 ppm max
Fe  ≤ 5 ppm max
Pb  ≤ 5 ppm max
Mg ≤ 5 ppm max

Trizma is a registered trademark of Sigma-Aldrich Co.

支持材料

Tris Buffer HR2-589 Tris SDSTris Buffer HR2-725 Tris pH 8.5 SDSTris Buffer Titration Table

相关项目

  • Hydrochloric acid
  • StockOptions Tris Buffer Kit
  • Individual StockOptions Tris Reagents
  • 盐酸
    StockOptions Tris 缓冲套件
    个人股票期权 Tris 试剂

参考

1. Purification and crystallization of Pseudomonas aeruginosa chloramphenicol acetyltransferase. Tian, Y; Beaman, TW; Roderick, SL; Proteins 28, 298- 300, 1997.

1. 铜绿假单胞菌氯霉素乙酰转移酶的纯化与结晶。 田,Y; 比曼,台湾; 罗德里克,SL; 蛋白质 28, 298-300, 1997。