General Guidelines for Handling DNA

Working with DNA: Good laboratory practice

DNA is a relatively stable molecule, but it is still important to avoid introducing nucleases to your plasmid solutions as these enzymes will degrade DNA. You should also store your DNA samples in TE buffer to avoid acid hydrolysis when stored in water.
Molecular weight conversions for DNA

MW of a double-stranded molecule (sodium salt) = (number of base pairs) x (662 daltons/base pair)

Molecular conversions for DNA
Exemplary molar conversions for (plasmid) DNA can be found in the tables Microgram DNA conversions and Picomole DNA conversions. Protein/DNA conversions can be found in the table Protein/DNA conversions.
Microgram DNA conversions
1 µg pmol Molecules
20 b oligonucleotide 152 9.1 x 1013
1000 bp DNA 1.52 9.1 x 1011
pUC 19 DNA (2686 bp) 0.57 3.4 x 1011
pBR322 DNA (4263 bp) 0.35 2.1 x 1011
Lambda DNA (48,502 bp) 0.03 1.8 x 1010

Picomole DNA conversions
1 pmol Micrograms
20 b oligonucleotide 0.0066
1000 bp DNA 0.66
pUC 19 DNA (2686 bp) 1.77
pBR322 DNA (4263 bp) 2.88
Lambda DNA (48,502 bp) 32.01

Protein/DNA conversions
1 pmol DNA
10,000 Da 270 bp
30,000 Da 810bp
100,000 Da 2.7 kb