细菌的生化试验 (也称生化反应) 是指由于不同细菌具有各自的酶系统，对底物的分解能力不同，由此产生的代谢产物也不同，通过生物化学的方法测定这些代谢产物的过程。生化试验主要包括碳水化合物的生化试验、氨基酸和蛋白质的代谢试验、碳源和氮源的利用试验、酶类的代谢试验等。不同的细菌对蛋白质的分解能力不同，一般先由胞外酶把蛋白质分解为短肽或氨基酸，侵入细菌体内后由胞内酶把肽类分解为氨基酸。这一分解过程可以通过氨基酸和蛋白质的代谢试验来检测，其中吲哚试验就是典型的过氨基酸和蛋白质的代谢试验。
阿拉丁Ehrlich试剂又称吲哚试剂或靛基质试剂，其效成分为对二苯甲氨基甲醛，加入Ehrlich试剂后形成红色的玫瑰吲哚。吲哚试验原理是某些具有色氨酸酶的细菌能够分解蛋白胨水中的色氨酸生成吲哚 (靛基质)，吲哚与对二苯甲氨基甲醛结合，形成红色化合物玫瑰吲哚。Ehrlich试剂特别适用于肠杆菌科细菌、非发酵菌、寄养性细菌、厌氧菌的鉴定。
自备材料：
1、试管
2、胰胨培养基
3、恒温培养箱
操作步骤（仅供参考）：
1、将待检细菌接种于胰胨培养基，置于恒温培养箱35～37°C培养24～48h。
2、沿试管壁缓慢加入1ml乙醚或二甲苯，摇匀试管以便提取和浓缩吲哚，直至红色吲哚浮于培养基表面。
3、沿试管壁缓慢加入数滴Ehrlich Reagent，观察其与培养基接触面的颜色变化。
注意：加入Ehrlich Reagent后不宜再摇动，否则液体界面倍混合，红色环不明显。
染色结果：
注意事项：
1、培养细菌时，注意避免污染。
2、Ehrlich试剂仅用于科研目的，不可用于临床诊断。
3、为了您的安全和健康，请穿实验服并戴一次性手套操作。
Bacterial biochemical tests (also referred to as biochemical reactions) refer to the process of determining these metabolic products via biochemical methods. This is based on the fact that different bacteria possess distinct enzyme systems, leading to varied abilities to decompose substrates and thus producing different metabolic products. Biochemical tests mainly include carbohydrate biochemical tests, amino acid and protein metabolism tests, carbon and nitrogen source utilization tests, enzyme metabolism tests, etc. Different bacteria vary in their capacity to decompose proteins. Generally, extracellular enzymes first break down proteins into short peptides or amino acids. After these substances enter bacterial cells, intracellular enzymes further decompose the peptides into amino acids. This decomposition process can be detected through amino acid and protein metabolism tests, among which the indole test is a typical example of such tests.
Aladdin Ehrlich’s Reagent, also known as indole reagent or indican reagent, has p-dimethylaminobenzaldehyde as its active component. Adding Ehrlich’s Reagent will result in the formation of red rosindole. The principle of the indole test is that certain bacteria containing tryptophanase can decompose tryptophan in peptone water to produce indole (indican). Indole combines with p-dimethylaminobenzaldehyde to form rosindole, a red compound. Ehrlich’s Reagent is particularly suitable for the identification of Enterobacteriaceae, non-fermenting bacteria, parasitic bacteria, and anaerobic bacteria.
Materials to be Prepared by the User:
1. Test tubes
2. Tryptone medium
3. Constant-temperature incubator
Operating Procedures (For Reference Only):
1. Inoculate the test bacteria into the tryptone medium and incubate it in a constant-temperature incubator at 35–37°C for 24–48 hours.
2. Slowly add 1 ml of ether or xylene along the inner wall of the test tube, then shake the tube thoroughly to extract and concentrate indole until the red indole floats on the surface of the medium.
3. Slowly add several drops of Ehrlich Reagent along the inner wall of the test tube, and observe the color change at the contact surface between the reagent and the medium.
Note: Do not shake the tube again after adding Ehrlich Reagent; otherwise, the liquid interface will mix, and the red ring will become indistinct.
Staining Results:
Red
| Positive
|
No color change
| Negative
|
Precautions:
1. Take care to avoid contamination when culturing bacteria.
2. Ehrlich’s reagent is intended for research purposes only and not for clinical diagnosis.
3. For your safety and health, wear a lab coat and disposable gloves during the operation.
ZJ25F1230694
危险品化学品经营许可证（带存储）