Obtained 4 microcentrifuge tubes.
Labeled two tubes A and two tubes B for respective samples
Filled each microcentrifuge tube with 1.5 mL of respective bacterial culture
Centrifuged all 4 samples at 13,000 rpm for 3 minutes
Decanted the supernatant
Resuspended the bacterial pellets in 0.25 mL of Buffer P1
Added 0.25 mL of Buffer P2 after resuspension
Mixed the solution by inverting tube until solution was homogeneous blue
Incubated samples for no more than 3 minutes
Added 0.35 mL of Buffer N3
Mixed the samples immediately until solution becomes colorless
Centrifuged samples for 10 minutes at 11,000 rpm
Transferred the supernatant to spin column
Centrifuged for additional 2 minutes at 11,000 rpm
Discarded the flowthrough into waste receptacle
Applied 0.5 mL of Buffer PB to spin column
Centrifuged for additional 2 minutes at 11,000 rpm
Discarded the flowthrough into waste receptacle
Applied 0.75 mL of Buffer PE to spin column
Centrifuged samples for additional 2 minutes at 11,000 rpm
Discarded the flowthrough into waste receptacle
Centrifuged for additional 2 minutes at 11,000 rpm until all residual fluid was removed from column
Placed spin columns into second microcentrifuge tubes
Added 50 μL of Buffer EB to columns
Incubated samples at room temperature for at least 1 minute
Centrifuged samples for additional 2 minutes at 11,000 rpm
Placed samples into microcentrifuge rack for storage