Editing Protein Purification using Magnetic Beads (section)

== Procedure: ==

Apply 1.3 ml of bacterial culture to a microfuge tube and spin for 5 min at 13,000 rpm. Store the pellet at -20°C<br> Add 300 µl of extraction buffer to the pellet, resuspend the cells and incubate the suspension for 30 min at room temperature.<br> Homogenize by sonicating the cell suspension for 3 min in the ultrasonic water bath.<br> Take 10 ml of the homogenate and store for SDS-PAGE analysis. Centrifuge the rest for 10 min at 13,000 rpm.<br> Remove the supernatant and discard the pellet. Take a 10-µl sample of the supernatant for SDS-PAGE analysis.<br> Pipette the rest of the supernatant to the prepared magnetic beads (in a 1.5-ml microfuge tube) and incubate the tube in the rocking device for 30 min at room temperature.<br> Apply the magnet and remove the supernatant.<br> Wash the beads with 300 µl washing buffer for 30 min at room temperature using the rocking device.<br> Then, wash the beads with 300 µl of PBS for 10 min.<br> Pipette 12 µl SDS sample buffer to the beads and boil for 3 min.<br> Mix the homogenate and supernatant samples (10 µl) with 10 µl SDS sample buffer and boil for 3 min.<br> Analyze the samples [homogenate (total protein), supernatant (soluble protein) and purified protein] by SDS-PAGE.

<br>