Shopping Cart (0)
$0.00

You have no items in your shopping cart.

Fast Facts

Formula for Calculation of Primer Melting Temperature (Tm)

Tm (°C) = 81.5 + 16.6(logM) + 0.41(%GC) - (500/n)
n = length of primer
M = molarity of the salt in the buffer

Formula for Calculation of nmoles of 5’ or 3’ ends per µl of nucleic acid sample

nmoles ends = A/(BxC) x 1000 nmoles/µmol
A = the concentration of nucleic acid (µg/µl)
B = average molecular weight of nucleotide (333 µg/ µmol for DNA; 317 µg/ µmol for RNA)
C = total number of bases (for ssDNA or RNA) or base pairs (for dsDNA)

Characteristics of Common Proteins

ProteinMolecular WeightSubunitspIExtinction coefficient 
at 280 nm (at 1 mg/ml)
Optimal pH 
(for enzymes)
Alkaline Phosphatase (calf intestinal) 140,000  2  5.7  1.0  9.5
Avidin 68,000  4  10  1.54  -
BSA  67,000  1  4.9  0.67  -
GFP  25,000  1  5.0  1.05  -
Glucose Oxidase  160,000  2  4.2  1.38  5.5
Horseradish Peroxidase  40,000  1  7.2  0.63  7.0
Immunoglobulin G (IgG)  150,000  4  5-12  1.34  -
Streptavidin  60,000  4  5.5  3.4  -

Spectrophotometric Conversions of Nucleic Acids

1 A260 of dsDNA = 50 µg/ml = 0.15 mM (in nucleotides)
1 A260 of ssDNA = 33 µg/ml = 0.1 mM (in nucleotides)
1 A260 of ssRNA = 40 µg/ml = 0.11 mM (in nucleotides)

MWaverage of a deoxyribonucleotide = 333 g/mol

MWaverage of a ribonucleotide = 350 g/mol

Weight Conversion

1 mg = 10-3 gm
1 µg = 10-6 gm
1 ng = 10-9 gm
1 pg = 10-12 gm
1 fg = 10-15 gm
1 ag = 10-18 gm

Amino Acid Symbols:

A Alanine G Glycine P Proline
R  Arginine  H  Histidine  S  Serine
N  Asparagine  I  Isoleucine  T  Threonine
D  Aspartic Acid  L  Leucine  W  Tryptophan
C  Cysteine  K  Lysine  Y  Tyrosine
Q  Glutamine  M  Methionine  V  Valine
E  Glutamic Acid  F  Phenylalanine