5-3.1.2(b). Advantages

• No requirement of a marker gene.
  
  
• Introduction ofthe target gene directly into a single cell.
  
  
• Easy identification of transformed cells upon injection of dye along with the DNA.
  
  
• No requirement of selection of the transformed cells using antibiotic resistance or herbicide resistance markers.
  
  
• It can be used for creating transgenic organisms, particularly mammals.

5-3.1.3. Particle bombardment

• Prof Sanford and colleagues at Cornell University (USA) developed the original bombardment concept in 1987 and coined the term “biolistics” (short for “biological ballistics”) for both the process and the device.
  
  
• Also termed as particle bombardment, particle gun, micro projectile bombardment and particle acceleration.
  
  
• It employs high-velocity micro projectiles to deliver substances into cells and tissues.

5-3.1.3(a). Uses

• This method is commonly employed for genetic transformation of plants and many organisms.
  
  
• This method is applicable for the plants having less regeneration capacity and those which fail to show sufficient response to Agrobacterium- mediated gene transfer in rice, corn,wheat, chickpea,sorghum and pigeon-pea.

5-3.1.3(b). Apparatus

The biolistic gun employs the principle of conservation of momentumand uses the passage of helium gas through the cylinder with arrange of velocitiesrequired for optimal transformation of various cell types. It consists of a bombardment chamber which is connected to an outlet for vacuum creation. The bombardment chamber consists of a plastic rupture disk below which macro carrier is loaded with micro carriers. These micro carriers consist of gold or tungsten micro pellets coated with DNA for transformation.