Why does the yield differ between syntheses of the same sequence or length oligo?
The yield has many contributing factors. The primary reason why you might see different yields for the same oligo is that the columns are not loaded with exactly the same quantity of CPG. For example, a 50 nmol column will have a minimum of 50 nmols of 3′ base available to start synthesis, but frequently has more than this amount. Keep in mind this is the starting scale and not the final yield.
