Inform your doctor if you are on any medications, have any allergies or underlying medical conditions before your C-Peptide Response To Glucose 5 Hours Chemilumensence/ Spectophotometry - Hexokinase Blood Serum. Your doctor will give specific instructions depending on your condition on how to prepare for C-Peptide Response To Glucose 5 Hours Chemilumensence/ Spectophotometry - Hexokinase Blood Serum.