Seed Vitality Test Kit (Bromothymol Blue BTB Method)

Cat. No.: S1509461

GRADE & PURITY BioReagent

Overview

Seed Viability refers to the potential ability of seeds to germinate or the vitality of the seed embryo. Its level determines seed quality and practical value, and is related to the seeding rate. A common method for assessing seed viability is the germination test, where seeds are allowed to absorb water and germinate under suitable conditions, and the percentage of germinated seeds out of the total tested is counted within a specified period. However, conventional germination tests are time-consuming, cannot meet urgent needs, and cannot detect the viability of dormant seeds. Faster detection methods commonly used include the Tetrazolium Chloride (TTC) method, Bromothymol Blue (BTB) method, red ink staining method, and fluorescence method.

Viable seed embryos respire, taking up oxygen from the air and releasing carbon dioxide. The carbon dioxide dissolves in water to form carbonic acid, which dissociates into hydrogen ions and bicarbonate ions, thereby increasing the acidity around the embryo. This change in acidity can be qualitatively measured using Bromothymol Blue (BTB). The color transition range of BTB is pH 6.0–7.6: it appears yellow in an acidic medium and blue in an alkaline medium, with green as the intermediate color (transition point at pH 7.1). Therefore, seed viability can be judged based on the color difference of BTB. This method offers the following advantages: rapid, accurate; obvious color change, easy to observe. This kit is for research use only and is not suitable for clinical diagnosis or other purposes.

Reagents, consumables and Equipments not provided

• Incubator, culture dish
• Materials: Plant seeds such as wheat, mung bean, rice, rapeseed, peanut, corn, etc.
  

Operating Steps (For Reference Only)

1. Soaking Seeds: Soak the test seeds in 30°C warm water for 2–6 hours to allow full imbibition.

2. Preparation of BTB-Agar Gel: Take appropriate amounts of BTB Indicator and agar powder. Mix at a ratio of 10 mL BTB Indicator to 0.15 g agar powder. Heat using an incubator or microwave to aid dissolution. Once the agar powder is completely dissolved, pour the hot solution into a clean culture dish to form the BTB-agar gel. The thickness should be sufficient to submerge the seeds. Let it cool for use.

3. Randomly take 100 imbibed seeds. Place them with the embryo side down, neatly embedded in the BTB-agar gel, with a spacing of at least 1 cm between seeds.

4. Place the culture dish in an incubator at 30–35°C for 1–4 hours.

5. Observe against a blue or green background. Seeds with a distinct yellow halo near the embryo are viable; otherwise, they are dead.

6. Seeds treated by boiling water immersion can be used as a control for observation.

Staining Results

Viable Seed	Yellow or yellow-green color appears near the embryo
Dead Seed	No color change near the embryo

7. Calculation:

Observe and count 100 seeds. Calculate the percentage of viable seeds using the formula:

Seed Viability Percentage (%) = (Number of viable seeds / 100) × 100%

Precautions

1. The thickness of the BTB gel depends on seed size. In principle, it should ensure that after the embryo contacts the bottom of the dish, part of the seed remains above the gel. The gel thickness should hold the seeds stably.

2. Seeds must be intact, without damage or mold.

3. The BTB Indicator should be a green or blue solution, with a pH preferably between 7.1–8.5. If it turns yellow or yellow-green, indicating a pH drop, add a small amount of dilute ammonia water or sodium hydroxide solution to adjust the pH back to normal. A pH that is too high is also not conducive to observing color changes.

4. The incubation temperature is generally 30–35°C.

5. Please use the reagent as soon as possible after opening to avoid affecting subsequent experimental results.

Storage and Shipping

Storage

Room temperature

Shipped In

Normal

Stability And Storage

Store at room temperature long term (12 months).

Contents & Storage

S1509461	Component	100 mL	Storage
S1509461A	BTB Indicator	100 mL	RT.
S1509461B	Agar Powder	1.5 g	RT.