摘要
为达到α－淀粉酶（α－ＡＭＳ）测定的最好的准确性和精密度，最大线性范围及与酶法的可比性，进行了碘－淀粉吸光系数标准化法测定淀粉酶的实验研究。底物浓度改为０．７９ｇ／Ｌ，底物缓冲液以Ｔｒｉｓ－ＨＣｌ（ｐＨ７．０，３７℃，５０ｍｍｏｌ／Ｌ）为缓冲剂，并加入２．５ｍｍｏｌ／ＬＣａＣｌ２和１００ｍｍｏｌ／ＬＮａＣｌ以保证对α－ＡＭＳ的激活作用，酶促反应时间选为５ｍｉｎ，测定波长选定为７００（或８００／７００）ｎｍ。本法线性测定范围达２０００ＩＵ／Ｌ以上，标本溶血、黄疸及乳糜对测定结果无影响；本法与酶法相关关系密切（ｎ＝２３，ｒ＝０．９９８８，Ｙ＝１．０１６ｘ－１９），并以一定的关系式求得酶法（ＰＮＰＧ７法）测定值（ＩＵ／Ｌ）做报告；实验参数可手法操作及自动分析两用，适于各型医院实验室推广应用。本法参考值：血清（ｎ＝１１３）α－ＡＭＳ＜９３．４ＩＵ／Ｌ，尿液（ｎ＝１４２）α－ＡＭＳ＜６２２ＩＵ／Ｌ。
α amylase activity of serum and urine was determined with iodine starch absorption coefficient standardized method in our experiment. The limited substrate was starch calibrated with appointed starch, the wavelength was 700 nm or 800 nm, the result was reported with PNPG 7 limited substrate enzymatic activity. According to our method, the reference value of serum was less than 93 IU/L, and the reference value of random urine was less than 622 IU/L in healthy adult. The comparison of α amylase activity in urine between our method (report value Y) and PNPG 7 method (determined value X) showed that: Y=1.016 X-19, r =0.9988, n =23,=460.9, =448.6, the relationship between the α amylase activity and absorbance was negatively linear correlative. The results with our method were not effected by bilirubin, triglyceride, and free hemoglobuline. Our method had many characteristics such as standardization of starch substrate, one time expansion of linear range with calculating method of iodine starch absorption coefficient, good precision, reliable results, equivalence of enzyme activity unit to enzymic international unit, comparable to PNPG 7 method, long period stability of reagent, operation being simple and rapid and suitable for manual and automatic analysis, so the method was applicable to large, middle or small scale hospital laboratories.
出处
《中国医科大学学报》
CAS
CSCD
1996年第5期522-525,共4页
Journal of China Medical University
关键词
Α-淀粉酶
碘-淀粉
吸光系数
标准化法
α amylase
iodine starch absorption coefficient
standardization
