FAQ: What size gDNA can be purified with the Monarch® Genomic DNA Purification Kit?

Assuming high quality input material has been used, the peak size of gDNA isolated with this kit ranges from 50-60 kb. Typical DNA Integrity Numbers (DINs) for gDNA isolated from blood, cells or tissues are around 9.0. The Monarch gDNA purification protocol is optimized for isolation of gDNA that is larger than that isolated by other commercial kits. For example, it includes elution with preheated buffer that enhances the elution of larger pieces of DNA.

Some starting materials such as buccal swabs or saliva, however, contain a significant proportion of dead cells. In those cells, apoptotic mechanisms have activated nucleases that digest the gDNA to shorter fragments. The peak size of gDNA isolated from such samples is usually in the range 20-40 kb.