1. Physical constants of nucleoside triphosphates
Compound | Molecular weight | λmax(pH7.0) | Maximum absorption value at λmax in 1 molar solution (pH 7.0) | OD 280 /OD 260 |
ATP | 507 | 259 | 15400 | 0.15 |
CTP | 483 | 271 | 9000 | 0.97 |
GTP | 523 | 253 | 13700 | 0.66 |
UTP | 484 | 262 | 10000 | 0.38 |
dATP | 494 | 259 | 15200 | 0.15 |
dCTP | 467 | 271 | 9300 | 0.98 |
dGTP | 507 | 253 | 13700 | 0.66 |
dTTP | 482 | 267 | 9600 | 0.71 |
2. Length and molecular weight of commonly used nucleic acids
Nucleic Acids | Number of nucleotides | Molecular weight |
λDNA | 48502 (double chain ring) | 3.0×10 7 |
pBR322 | 4363 (double chain) | 2.8×10 6 |
28S rRNA | 4800 | 1.6×10 6 |
23S rRNA | 3700 | 1.2×10 6 |
18S rRNA | 1900 | 6.1×10 5 |
19S rRNA | 1700 | 5.5×10 5 |
5S rRNA | 120 | 3.6×10 4 |
tRNA (E. coli) | 75 | 2.5×10 4 |
3. Commonly used nucleic acid-protein conversion data
(1) Weight conversion
1μg=10-6 g 1pg=10-12 g
1ng=10 -9 g 1fg=10 -15 g
(2) Spectrophotometric conversion:
1A 260 double-stranded DNA = 50 μg/ml
1A 260 single-stranded DNA = 30 μg/ml
1A 260 single-stranded RNA = 40 μg/ml
(3) DNA molar conversion:
1μg 100bp DNA = 1.52pmol = 3.03pmol ends
1 μg pBR322 DNA = 0.36 pmol
1pmol 1000bp DNA = 0.66μg
1pmol pBR322 = 2.8μg
1kb double-stranded DNA (sodium salt) = 6.6×10 5 Daltons
1kb single-stranded DNA (sodium salt) = 3.3×10 5 Daltons
1kb single-stranded RNA (sodium salt) = 3.4×10 5 Daltons
(4) Protein molar conversion:
100 pmol of a protein with a molecular weight of 100,000 = 10 μg
100 pmol of a protein with a molecular weight of 50,000 = 5 μg
100 pmol of molecular weight 10,000 protein = 1 μg
The average molecular weight of amino acids = 126.7 Daltons
(5) Protein/DNA conversion:
1kb DNA = 333 amino acids Coding capacity = 3.7×10 4 MW protein
10,000MW protein = 270bp DNA
30,000MW protein = 810bp DNA
50,000MW protein = 1.35kb
100,000MW protein = 2.7kb DNA
4. Commonly used protein molecular weight standard reference substances
| (1) High molecular weight standard reference | (2) Medium molecular weight standard reference | (3) Low molecular weight standard reference | |||
| Myosin | Molecular weight | Phosphorylase B | 97,400 | Carbonic anhydrase | 31,00 |
| Myosin | 212,000 | BSA | 66,200 | Soybean proteinase | 21,500 |
| β-galactosidase B | 116,000 | Glutamine dehydrogenase | 55,000 | Inhibitors | |
| Phosphorylase B | 97,400 | Ovalbumin | 42,700 | Horse myocardial globulin | 16,900 |
| BSA | 66,200 | Aldolase | 40,000 | Lysozyme | 14,400 |
| Catalase | 57,000 | Carbonic anhydrase | 31,000 | Myosin (F1) | 8,100 |
| Aldolase | 40,000 | Soybean proteinase | 21,500 | Myosin (F2) | 6,200 |
| Inhibitors | Myosin (F3) | 2,500 | |||
| Lysozyme | 14,400 | ||||
5. Commonly used DNA molecular weight standard reference materials
λDNA/HindⅢ | λDNA/EcoRⅠ | λ/HindⅢ+EcoRⅠ | pBR322/HaeⅢ | |
23130 | 21226 | 21227 | 587 | 123 |
9416 | 7421 | 5148 | 405 | 104 |
6557 | 5804 | 4973 | 504 | 89 |
4361 | 5643 | 4268 | 458 | 80 |
2322 | 4843 | 3530 | 434 | 64 |
2027 | 3530 | 2027 | 267 | 57 |
564 | 1904 | 234 | 51 | |
125 | 1584 | 213 | twenty one | |
1375 | 192 | 18 | ||
974 | 184 | 11 | ||
831 | 124 | 7 | ||
564 | ||||
125 | ||||
Continued from the table above
pBR322/HinfⅠ | φχ174/HinfⅠ | φχ174/Hae Ⅲ | φχ174/TapⅠ | |
1631 | 726 | 140 | 1353 | 2914 |
517 | 713 | 118 | 1078 | 1175 |
506 | 553 | 100 | 872 | 404 |
396 | 500 | 82 | 603 | 327 |
344 | 417 | 66 | 310 | 231 |
298 | 413 | 48 | 281 | 141 |
221 | 311 | 42 | 271 | 87 |
220 | 249 | 40 | 234 | 54 |
154 | 200 | twenty four | 194 | 33 |
75 | 151 | 118 | 20 | |
72 | ||||
