Dear Santanu

• if this is following a 70% wash of precipitated plasmid DNA then simply leaving at room temp for 20 min will dry the pellet 
• Dried pelleted DNA if pure will turn clear
• to maximise chances of obtaining pure DNA with 70% ethanol removed before air drying then having removed most of the 70% ethanol following precipitation and wash spin pellet for 5 min at 13k; remove most of the ethanol; spin again for 1 minute and remove residual ethanol by using a narrow bore tip ( like a p10 tip). 
• This will allow your pellet to dry within 20 min at room temp
• if you dry DNA pellets at 70C this will aggressively evaporate 70% ethanol but can then over dry the pellet which then makes it difficult to dissolve 

Dear Santanu

• if this is following a 70% wash of precipitated plasmid DNA then simply leaving at room temp for 20 min will dry the pellet 
• Dried pelleted DNA if pure will turn clear
• to maximise chances of obtaining pure DNA with 70% ethanol removed before air drying then having removed most of the 70% ethanol following precipitation and wash spin pellet for 5 min at 13k; remove most of the ethanol; spin again for 1 minute and remove residual ethanol by using a narrow bore tip ( like a p10 tip). 
• This will allow your pellet to dry within 20 min at room temp
• if you dry DNA pellets at 70C this will aggressively evaporate 70% ethanol but can then over dry the pellet which then makes it difficult to dissolve 

Instead of incubation at 70 degree, i will suggest keeping tubes opened in Laminar Air Flow for 30 minutes is one of the option for pellet drying

I found that air drying is better rather than keeping it in incubation