I. Prepare oligo-dT cellulose
* use 40 mg oligo-dT cellulose / 1 mg total RNA
* swell oligo dT-cellulose in elution buffer
* wash oligo dT-cellulose 4 x with elution buffer (30 sec. full speed spin in between)
* equilibrate oligo-dT cellulose with 2 to 3 washing steps using 1x binding buffer
II. mRNA purification
* bring 1 mg total RNA with H2O to 600 µl
* incubate 4 min at 65 °C
* add 600 µl 2x binding buffer
* add to 40 mg 1x binding buffer equilibrated oligo-dT cellulose
* incubate 15 min at RT on a rolling incubator or vortex several times in between
* spin oligo-dT cellulose down, discard supernatant
* wash 2 x with 1x binding buffer
* wash 2 x with wash buffer
* elute with 250 µl elution buffer at 37 °C for 5 min
* spin and keep supernatant (for second round of purification or precipitation)
* elute oligo-dT cellulose again with 250 µl elution buffer
* spin and keep supernatant (for second round of purification or precipitation)
* combine eluate and add H2O to 600 µl
* repeat mRNA purification by starting again with 4 min incubation at 65 °C