- 背景資料
酵母可同化氮(yeast assimilable nitrogen，簡稱YAN)，涵義為酵母菌在發酵時可利用的氮含量測定，常用於監測葡萄酒的酒精發酵過程。YAN主要由3種成分所構成，分別為:
↪️游離的銨離子free ammonium ions➡️No. K-URAMR測量
↪️primary amino nitrogen (from free amino acids) ➡️No. K-PANOPA測量
↪️L-精氨酸(L-arginine)側鏈➡️No. K-LARGE測量(此套組)
- 操作方式(PROCEDURE)
- 樣品準備 (SAMPLE PREPARATION)
1. Sample dilution.
The amount of analyte present in the cuvette (i.e. in the 0.1 mL of sample being analysed) should range between 0.2 and 7.0 µg (ammonia), 0.3 and 14 µg (urea) and 1.0 and 35 µg (L-arginine). The sample solution must therefore be diluted sufficiently to yield concentrations of ammonia between 0.01 and 0.08 g/L, urea between 0.02 and 0.14 g/L, and L-arginine between 0.05 and 0.40 g/L.
2. Sample clarification.
Carrez reagents cannot be used for deproteinisation as their use results in significantly reduced recoveries. Perchloric or trichloroacetic acid are used as alternatives.
3. General considerations.
(a) Liquid samples: clear, slightly coloured and approximately neutral, liquid samples can be used directly in the assay.
(b) Acidic samples: if > 0.1 mL of an acidic sample is to be used undiluted (such as wine or fruit juice), the pH of the solution should be increased to approx. 8.0 using 2 M NaOH, and the solution incubated at room temperature for 30 min.
(c) Carbon dioxide: samples containing a significant amount of carbon dioxide, such as beer, should be degassed by increasing the pH to approx. 8.0 with 2 M NaOH and gentle stirring, or by stirring with a glass rod.
(d) Coloured samples: an additional sample blank, i.e. sample with no GlDH, may be necessary in the case of coloured samples.
(e) Strongly coloured samples: if used undiluted, strongly coloured samples should be treated by the addition of 0.2 g of polyvinylpolypyrrolidone (PVPP) per 10 mL of sample. Shake the tube vigorously for 5 min and then filter through Whatman No. 1 filter paper. (f) Solid samples: homogenise or crush solid samples in distilled water and filter if necessary.
商品特色
商品規格
- 商品規格 50 個檢測反應
Bottle 1:
Buffer (18 mL, pH 8.0) plus sodium azide (0.02% w/v) as a preservative.
Stable for > 2 years at 4°C.
Bottle 2:
NADPH.
Lyophilised powder. Stable for > 5 years below -10°C.
Bottle 3:
Glutamate dehydrogenase suspension (1.1 mL).
Stable for > 2 years; store sealed at 4°C.
Bottle 4:
Urease solution (2.7 mL).
Stable for > 2 years below -10°C.
Bottle 5:
Arginase suspension (1.1 mL).
Stable for > 2 years; store sealed at 4°C.
Bottle 6:
Ammonia (0.04 mg/mL) standard solution.
Stable for > 2 years; store sealed at 4°C.
Bottle 7:
L-Arginine powder (2 g) standard.
Stable for > 2 years stored dry at 4°C.
