Column clogging may occur due to the sample being too large. Do not exceed the recommended amount of starting materials. The amount of starting material may need to be decreased if the column shows clogging below the recommended levels. Clogging can also be alleviated by increasing the g-force and/or centrifuging for a longer period of time until the lysate passes through the column.

Lysate can be more gelatinous prior to loading onto the column due to the following factors:

• The lysate solution mixture is not homogeneous. To ensure a homogeneous solution, vortex for 10-15 seconds before applying the lysate to the spin column.
• Maximum number of cells or amount of tissue exceeds kit specifications. Refer to specifications to determine if the amount of starting material falls within kit specifications.

A low genomic DNA yield may be caused by:

• Improper storage of samples. Tissue samples and cell pellets may be frozen and stored at -20°C or -70°C. Repeated freezing and thawing of stored samples should be avoided, as this may lead to decreased yields of DNA.
• Incomplete lysis of cells. Extend the incubation time of Proteinase K digestion or reduce the amount of tissue or cells used for lysis.
• The DNA elution is incomplete. Ensure that centrifugation at 14,000 x g is performed after the 3,000 x g centrifugation cycle, to ensure that all the DNA is eluted.

Shearing of genomic DNA can be due to the following reasons:

• The genomic DNA was handled improperly. Pipetting steps should be handled as gently as possible. Reduce vortexing times during mixing steps (no more than 10-15 seconds).
• Improper storage of sample. Repeated freezing and thawing of stored samples should be avoided as this may lead to decreased DNA size.
• The sample is old. Sheared DNA may be obtained from old tissue or cell samples. Fresh samples are recommended for maximum genomic DNA yield.

Yes, mitochondrial DNA (mtDNA) can be successfully isolated using this kit. Please contact our Tech support team at support@norgenbiotek.com and ask for reference publications.