Q: We recently spoke to you about performing a custom saporin conjugation using our antibody. Is 0.09% azide in PBS in the antibody stock acceptable?
A: There are a number of dialysis steps within the conjugation protocol that will ultimately remove the azide from your antibody solution. So as long as your antibody will be happy in PBS without azide during the procedure, sending the material in 0.09% azide is fine. The final conjugate will be returned to you in PBS, sterile-filtered, without azide.
Q: In general, how many saporin molecules are incorporated per antibody? Can we test this by HPLC?
A: We aim for 2-2.5 moles of saporin per mole of antibody. You should be able to see differences in HPLC between your antibody with one vs. two vs. three saporins attached, however we will provide you with a saporin molar ratio and a product that has had free saporin and free antibody removed from the final conjugate.
Related: Custom Conjugates