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Nucleic Acids and Protein Conversion Table

Molar, spectrophotometric and other usual conversions for nucleic acids and protein can be found here.

Metric Prefixes
Prefix Symbol Factor
kilo k 103
centi c 10-2
milli m 10-3
micro µ 10-6
nano n 10-9
pico p 10-12
femto f 10-15
atto a 10-18
zepto z 10-21

Spectrophotometric Conversions
1 A260 unit of double-stranded DNA=50 µg/ml
1 A260 unit of single-stranded DNA=33 µg/ml
1 A260 unit of single-stranded RNA=40 µg/ml

DNA Molar Conversions
1 µg of 1,000 bp DNA = 1.52pmol(3.03pmol of ends)
1 µg of pBR322 DNA = 0.36pmol DNA
1 pmol of 1,000 bp DNA = 0.66 µg
1 pmol of pBR322 DNA = 2.8 µg

Formulas for DNA Molar Conversions
For dsDNA
To convert pmol to µg:
pmol × N × 660 pg/pmol × 1 µg/106pg = µg
To convert µg to pmol:
µg × 106pg/1 µg × pmol/660pg × 1/N = pmol
For ssDNA
To convert pmol to µg:
pmol × N × 330 pg/pmol × 1µg/106pg = µg
To convert µg to pmol:
µg × 106pg/1 µg × pmol/330pg × 1/N = pmol
where N is the number of nucleotides and 330 pg/pmol is the average MW of a nucleotide

Protein Molar Conversions
100 pmol of 100 kDa protein = 10 µg
100 pmol of 50 kDa protein = 5 µg
100 pmol of 10 kDa protein = 1 µg
100 pmol of 1 kDa protein = 100 ng

Protein/DNA Conversions
1 kb DNA = 333 amino acids
  = 37 kDa protein
270 b DNA = 10 kDa protein
810 b DNA = 30 kDa protein
1.35 kb DNA = 50 kDa protein
2.7 kb DNA = 100 kDa protein
average MW of an amino acid = 110 daltons
Dalton (Da) is an alternate name for the atomic mass unit, and kilodalton (kDa) is 1,000 daltons. Thus a protein with a mass of 64 kDa has a molecular weight of 64,000 grams per mole

Agarose Gel(%):Resolution of Linear DNA
Recommended % Agarose Optimum Resolution for Linear DNA
(Size of fragments in nucleotides;bp)
0.5 1,000-30,000
0.7 800-12,000
1.0 500-10,000
1.2 400-7,000
1.5 200-3,000
2.0 50-2,000

Polyacrylamide Gel(%):Resolution of Protein
Recommended% Acrylamide Protein Size Range
8 40-200 kDa
10 21-100 kDa
12 10-40 kDa

Length/M.W. of Common Nucleic Acids.
Nucleic Acid Number of Nucleotides Molecular Weight
lambda DNA 48,502(dsDNA) 3.2 × 107
pBR322DNA 4,361(dsDNA) 2.8 × 106
28S rRNA 4,800 1.6 × 106
23S rRNA(E.coli) 2,900 1.0 × 106
18S rRNA 1,900 6.5 × 105
16S rRNA(E.coli) 1,500 5.1 × 105
5S rRNA(E.coli) 120 4.1 × 104
tRNA(E.coli) 75 2.5 × 104
*Molecular weights based on actual sequence.

Stardards
1. Average MW of dsDNA base pair = 600.
2. Average MW of ssDNA base =330.
3. Average MW of RNA base =340.