Ⅰ. Operating Steps:

1. Extract diluted sample:

Take out the bottle that contains the concentrated sample extract, add the purified water or mineral water purchased in the supermarket into the bottle, cover the bottle, and mix it upside down for 5 times to form the sample extract.

2. Sample preparation:

(1) Sample collection: Cut a thumbnail size leaf from a tobacco leaf with scissors and put it into the plastic bag provided.

(2) Sample grinding and homogenization: Suck 2 tubes of sample extraction solution (about 1 ml) with the provided straw and add it to the plastic bag containing leaves. After the plastic bag is sealed, rub the plastic bag with your hands like rubbing clothes until the leaves are completely crushed, and mix it in the sample extraction solution.

3. Sample Test:

Take out the test strip from the aluminum foil bag, lay it flat face up as shown in the figure below, and use a straw to absorb 3 drops of the sample extraction liquid prepared above into the sampling hole.

4. Result Interpretation:

The results were observed within 3 to 5 minutes. As shown in Figure 1 below, the color was positive at both line C (control line) and line T (detection line). As shown in Figure 2 below, color rendering only on line C and no color rendering on line T is negative. If neither line C nor line T is colored, or only line T is colored and line C is not colored, the test strip is invalid.

Ⅱ. Notes：

1. Store the test strip in a dry sealed aluminum foil bag and use it now.

2. Test strips are used for the detection of TMV in tobacco leaves.

3. Newly grown tobacco leaves with obvious symptoms should be collected during sampling. The symptoms of TMV-infected tobacco include: uneven leaf thickness, yellow and green flowers, dark brown necrotic spots in the later stage, wrinkled, deformed, distorted leaves in the heavily affected tobacco, and severe dwarfing in the early infected tobacco.

4. Take samples with scissors or blades. Disinfect with alcohol after each sample.

5. The colloidal gold test strip must be used with the sample extraction solution provided, and other sample extraction solutions cannot be used.

6. Each straw can only be used for the absorption and addition of 1 sample, and it is prohibited to use the same straw for the absorption and addition of multiple samples.

7. Dilute the sample extract and store it in refrigerator at 4℃ for later use.

Ⅲ. Storage conditions:

Store test strips in a cool dry environment away from light at 4-30℃. Do not freeze.

Ⅳ. Production Date and Expiration Date:

Production dates are detailed in the box. It is valid for 12 months.