ADAMS posted an update 2 weeks ago
[zymo gel extraction kit] I recently was having problems with this kit. The purified products always have high absorbance at 230nm or less. After contacting their technical support and practiced couple times, I finally figured out a way to avoid this. (1) do not use more than 400 mg of gel for each column. The columns seems to have a limited capacity to deal with the dissolved agarose, but I do not know the details about this. (2) use 750ul wash buffer instead of the suggested 200ul. This can help remove impurities remained on the wall of the column. The second wash uses 200ul, which can make sure the wash buffer is completely reomoved. (3) When adding dissolved gel solution, do not exceed 700ul each time, since higher volume can have agarose left on the wall, which cannot be washed easily by 750 ul of wash buffer. (4) Based on my own experience, it is better to wait until the dissolved solution is at room temperature before loading it to the column.