Superactive Latex Beads

These UltraClean latex beads are hydrophilic and contain a very high density of functional groups for covalent coupling of proteins to the particles. The superactive layer is a three-dimensional layer which increases the colloid stability of the particles and provides a 'soft landing' for the proteins. There is less distortion of the protein structure than if it were physically adsorbed to a rigid surface.

Carboxylate Modified (CML)

Type ID: 2     (pKa~variable, 5-9)     4% solids     Hydrophilic

Carboxylate modified latex beads are produced by copolymerizing carboxylic acid containing polymers. The result is a latex polymer particle with a highly charged, relatively hydrophilic and somewhat 'fluffy' surface layer. The charge density of the CML particles ranges from about 10 Å2 to 100Å2 per charged group. They are electrosterically stabilized, and are therefore safe in concentrations of electrolyte up to 1M univalent salt. CML modified latex beads are negatively charged with a surface which has a polyelectrolyte character. It is only when the pH is ~10 that all the carboxyl groups are ionized.

For large biomolecules, only the outermost groups are accessible, while a large portion of the carboxyl groups are “buried” underneath and are only accessible to small inorganic ions. Therefore the µeq/g data by titration can only be used as a reference to represent the maximum potential of reactive carboxyl groups. An area occupied by each carboxyl group on the outer surface can not be obtained from the titration data. This is a hydrophilic latex bead.

IDC latex beads


Type ID: 11     4% solids     Hydrophobic

The chloromethyl latex bead has a high density of chloromethyl groups attached to the styrene monomeric unit. These reactive surface functional groups react directly with amino groups in antibodies, antigens, or other ligands under mild aqueous conditions to yield a stable covalent product by a one-step process. The particles are stabilized by negatively-charged sulfate groups. This type of particle can be used at both high and low pH conditions. This is a hydrophobic latex bead. IDC latex beads


Type ID: 12     4% solids     Hydrophilic

These super-active latex beads contain an abundance of aldehyde groups grafted to the surface of the polymer particle. Typical aldehyde density is ~50 Ų/ group. The high density of aldehyde groups enables facile coupling of proteins and other materials to the latex particles in a one-step process. The sulfate charge groups on the microspheres enable retention of stability during the covalent coupling process. These particles are ideal candidates for a variety of applications in diagnostic kit production. This is a hydrophilic latex bead. IDC Latex Beads


Type ID: 5     4% solids

These particles are similar to aldehyde/sulfate latex beads, but with a positively-charged amidine functional group to provide colloidal stability. Typical aldehyde density is 100 Ų/group. This latex bead is not sensitive to multivalent cations.

Aliphatic Amine

Type ID: 6     2% solids

The aliphatic amine latex bead has a high density of amine groups attached to the terminus of an aliphatic six-carbon spacer arm. This latex particle can be used to covalently couple proteins. Location of the amine at the end of the spacer arm minimizes difficulties with steric hindrance and conformation since the group has a greater freedom to rotate. In addition, spacer arms improve the kinetics of latex agglutination reactions. The particles are stabilized by the positively-charged amine groups under low to neutral pH conditions. Care should be taken not to use them under high pH.


See catalog listings for uncolored, nonfluorescent particles

Browse our catalog to see all of our uncolored, nonfluorescent particles. Use the left-hand filters to narrow the products by bead type and surface modification.

Available bead types:

  • Super active latex beads
  • High activity latex beads
  • Specialty latex beads

Available surface modifications:

  • Aldehyde sufate
  • Aldehyde-amidine
  • Aliphatic amine
  • Amidine
  • Carboxyl
  • Chloromethyl
  • CML
  • DVB-amidine
  • DVB-carboxyl
  • DVB-sulfate
  • Nonionic beads
  • Sulfate