Re: Why do some things yield more DNA than others?

To answer the 'amount of DNA' issue, the amount of DNA present in different Eukaryotic genomes varies immensely from one species to the next. In eukaryotic genomes for example there are a lot of sequences that do not code for proteins. the C-Value Paradox basically describes the variation on Genome sizes in different eukaryotic cells.

In each species you will find a constant amount of genomic DNA and this is known as the C-Value for that species. this can vary immensely. for example Lewin in his textbook Genes IV states that the varition in C- values can be from as little as 10⁴ in Mycoplasma to 10¹¹ in some plants. Morevover this variation does not reflect the complexity of the organism. You can also find these large variations in Genome sizes between very cloesely related species. So, if the number and size of genes are the same between closely related species, why is there such a large variation in genome sizes and DNA quantities? Because Eukaryotic DNA contains a large amount of non coding sequences such as Repetitive sequneces. the variation in the amount of repetitive sequences goes some way to answering why there are variations in Genome sizes.

the second part of your question is a bit more difficult to answer as I do not know the specifics of your type of Prep. Here at Life Technologies we sell a product called DNAzol which can be used to isolate DNA from plants. you will find a full description of its use on our internet site on http://www.lifetech.com/ Content/Focus/202046.pdf. By using DNAzol the quality of DNAis extremely high and sufficient for most applications such as PCR.