Question

Hardening in tissue culture is :

• A. keeping at $30-50^{\circ }C$ temperature for about $30$ minutes
• B. acclimatisation of tissue culture plants slowly before growing in the field
• C. plunging the vials into water at $37-40^{\circ }C$
• D. none of the above

Answer 1

Answer: (B)

Hardening is the acclimatisation of plant formed by tissiue culture before growing in the field to make it strong to adapt in new environment. In cryopreservation the keeping of materials initially at $-30^{\circ }C$ to $-50^{\circ }C$ temperature for about $30$ minute and then cooled rapidly by plunging in liquid nitrogen is called freezing and storage.
The plunging of vials into water at $37^{\circ }C-40^{\circ }C$ for $90$ seconds is called thawing The material is then transferred into an ice bath till. it is recultured.