Blood DNA Isolation Mini Kit - Frequently Asked Questions

  1. Why is my spin column becoming clogged?
    1. Inefficient cell lysis - Check Proteinase K activity. Be sure to store the stock solution at 2-8 °C immediately after use. Also ensure that correct volume of Lysis Solution was added to the blood sample.
    2. Cell debris may be clogging the column - When a high cell number is expected in the blood sample, ensure that the optional spin step after the Proteinase K incubation is performed. Take the clean supernatant only for the next binding step.
    3. The sample is too large - Too many cells were applied to the column. Ensure that the correct volume of Proteinase K and Lysis Solution are added. Vortex proteinase K before use. Clogging can be alleviated by centrifuging for a longer period of time until the lysate passes through the column.
  2. Why is my yield of genomic DNA low?
    1. Inefficient cell lysis - Ensure that correct volume of Lysis Solution was added to blood sample. Also increase the proteinase K incubation time by additional 5-10 minutes at the specified incubation temperature.
    2. Low DNA binding - Ensure ethanol is added to the lysate and mixed well before binding to the column.
  3. Why does the DNA not perform well in downstream applications?
    1. DNA was not washed three times with the provided Wash Solutions - Ensure the column was washed one time with Wash Solution I and two times with Wash Solution II. An additional wash with Wash Solution II can improve DNA performance in downstream applications, however it may reduce DNA yield.
    2. Ethanol carryover - Ensure that the dry spin under the Column Wash procedure is performed, in order to remove traces of ethanol prior to elution. Ethanol is known to interfere with many downstream applications.