1. What is an Explant?

An explant is the starting material for tissue culture, typically a piece of vegetative or reproductive plant tissue. It retains totipotency and, under the right conditions, can regenerate into a full plant.

Examples of explants include:

• Shoot tips

• Leaf segments

• Nodal or internodal sections

• Root tips

• Meristems

• Embryonic tissue

The success of your culture often begins with the right explant.

2. Choosing the Right Explant

Young, actively growing tissues are ideal—older tissues are often more contaminated or less responsive.

📌 Tissue Source and Culture Response

3. Preparing Explants for Culture

The preparation process is key to preventing contamination and maximizing viability.

Steps:

1. Wash in running tap water (removes debris)

2. Surface sterilize with:

   • 70% ethanol (30 sec)

   • 5–10% bleach + 1 drop Tween-20 (5–10 min)

3. Rinse 3–5 times in sterile water

4. Trim in a laminar flow hood using sterile tools

5. Transfer to pre-poured culture medium

📌 Standard Surface Sterilization Techniques

4. Media and Conditions for Initiation

Explants are cultured on initiation medium tailored to the species and tissue type.

Environment:

• Temperature: 24–26°C

• Light: 16-hour photoperiod

• Humidity: 40–60% in incubation chamber

5. Early Culture Monitoring

After transfer:

• Watch for contamination signs within 48 hours

• Look for swelling, callus, or greening as indicators of success

• Remove and discard contaminated vessels immediately

• Record explant response for protocol optimization