Inform your doctor if you are on any medications, have any allergies or underlying medical conditions before your Jak 2 Mutation Panel (Exon 12 - 15) Analysis Pcr, Sanger Sequencing Blood. Your doctor will give specific instructions depending on your condition on how to prepare for Jak 2 Mutation Panel (Exon 12 - 15) Analysis Pcr, Sanger Sequencing Blood.