Characteristics of Polystyrene Particles
Density: 1.05
Refractive Index: 1.59
Composition: Linear polystyrene
Shape: Uniform microspheres
Porosity: Nonporous
Compatibility with organic solvent: Inert to alcohol and DMSO but soluble in DMF, acetone, acetonitrile, xylene, chloroform and methylene chloride.
Functional groups: Located on the surface with alkyl linker arms.
Functional group contents:
0.8 µm Carboxyl particles: ~ 50 µeq/g solid
0.8 µm Amino particles: ~ 15-20 µeq/g solid
Avidin Polystyrene Particle (0.8 µm):
Covalently coated with egg white avidin
Avidin Contents: ~ 14 µg/mg solid; ~ 0.212 nmole/mg solid
Binding capacity to Biotin-Fluorescein: ~ 0.46 nmole/mg solid
Antibody Coated Polystyrene Particles (0.8 µm):
Antibody contents: ~ 14 µg/mg solid; ~ 0.2 µg/cm2; ~1.5x104 IgG/particle
Binding capacity to IgG-FITC: ~ 4 µg/mg
Volume, Number and Surface Area vs. Particle Size
Volume of particle: V = (3.14/6) x D3 x 10-12 cm3/particle
Number of particles: N = (6W/3.14PD3) x 1012 particles
Surface area of particles: A = (6W/PD) x 104 cm2
Where
W = Weight of polymer in gram
P = Density of polymer (polystyrene = 1.05)
D = Diameter of particles in micrometer
Total surface area of 1 ml of 5% w/v (50 mg) particle:
A = 2857/D cm2
Total surface area of 20 µl of 0.25% w/v (50 µg) particles:
A = 2.857/D cm2
For 1 ml of 1% w/v (10 mg) particles
| DIAMETER (µm) | SURFACE AREA (cm2) | NUMBER (x109) |
| 0.05 | 11428 | 145513 |
| 0.1 | 5714 | 18189 |
| 0.5 | 1143 | 145.51 |
| 0.8 | 714 | 35.53 |
| 1 | 571 | 18.19 |
| 1.5 | 381 | 5.389 |
| 2 | 286 | 2.274 |
| 2.5 | 229 | 1.164 |
| 3 | 190 | 0.6737 |
| 3.5 | 163 | 0.4242 |
| 4 | 143 | 0.2842 |
| 4.5 | 127 | 0.1996 |
| 5 | 114 | 0.1455 |
| 5.5 | 104 | 0.1093 |
| 6 | 95 | 0.0842 |
| 6.5 | 88 | 0.06625 |
| 7 | 81 | 0.053 |
| 8 | 0.03552 | |
| 10 | 0.01819 | |
| 12 | 0.01052 | |
| 15 | 0.00539 |