实验纤维素酶活力的测定.doc

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实验 纤维素酶活力的测定〔3,5-二硝基水酸法〕
一、实验目的
掌握复原糖的测定原理，学习用3,5-二硝基水酸法测定纤维素酶活力的法。 
二、实验原理
e yellow amino pounds, so colorimetric method can be used to determine the reduction product e*pressed as cellulase activity .
3. The Main Instruments and Reagent
E*perimental Instrument
(1) 25mL colorimetric tube type (2).722 spectrophotometer
(3) dropper (4) bath (5) pipette (6) electric furnace

(1) 3,5- dinitro salicylic acid solution: Weigh 10 g 3,5- two nitro salicylic acid, dissolved in 200mL of distilled water, adding 20g sodium hydro*ide of analytically pure, 200g sodium potassium tartrate, add water to 500mL, heating to dissolve those reagents. Adding redistilled phenol , sodium sulfite anhydrous . Heating and stirring. When the reagents are fully dissolved, cooling. Dilute with water to 1000mL. Stored in a brown bottle, lay aside a week before use.
(2) acetic acid-sodium acetate buffer solution.
(3) %CMC-Na liquid: Weigh sodium carbo*ymethylcellulose, dissolved in water to make a colloidal solution, standing for a night. Shake well before using.
(4) glucose standard solution: weigh 100mg anhydrous glucose dried to constant weight, dissolvein water to100mL.
(5) Cellulase liquid: enzyme dissolvein 50 mL acetic acid-sodium acetate buffer solution, then suck to a 100mL volumetric flask，dilute with the buffer solution to scale.
4. E*perimental Steps
Standard Curve Drawing:
Adding , , , , , L glucose standard solution in 6 colorimetric tube of 25mL, respectively. In every colorimetric tube, adding distilled water until ,then adding - dinitro salicylic acid solution , boiled in boiling water bath 10min for color developing, then cooling, add 21mL of distilled water, shaking. Set empty tube zero, determine OD value at 550nm. Using the optical density as ordinate, glucose μg number as abscissa, to draw the s