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Binders for the surfaces your tests use.

Gemina’s library of over 50 dual-affinity binders (surface-binding proteins) attach capture molecules to the materials used in rapid tests and other assays, in a controlled orientation.

Why surface attachment matters

Capture molecules on a test line or plate do their job only when they face the target. Passive attachment leaves orientation to chance. A GemChem binder fixes the capture molecule to the surface by one end, so more of it is designed to remain available.

Capture antibodies attached passively on a test line, lying at random angles so many binding sites face the wrong way.

Passive attachment

Capture antibodies standing upright on GemChem binders on a test line, each holding a target and a gold-labelled detection antibody.

Controlled orientation with a GemChem binder

How a GemChem binder works

  1. A streptavidin or Protein G top binder is genetically fused to a surface-specific bottom binder, making a single protein.
  2. The bottom binder attaches to the material (cellulose, gold, polystyrene or glass), so the top binder faces outward in a controlled orientation.
  3. Your capture molecule binds to the top binder, ready to meet the target.
Capture molecule
Top binder: streptavidin or Protein G
Bottom binder
Material: gold, cellulose, polystyrene or glass

GemChem products

Cellulose-binding streptavidin

Attaches to
cellulose and nitrocellulose.
Capture molecule
biotinylated antibodies and other biotinylated molecules.
Designed for
test & control lines on nitrocellulose and cellulose supports.
Benefits
designed to increase test sensitivity while requiring less antibodies, and to simplify test development and manufacturing, resulting in better tests faster & cheaper.

Cellulose-binding Protein G

Attaches to
cellulose and nitrocellulose.
Capture molecule
antibodies (IgG), held by their Fc region.
Designed for
test & control lines on nitrocellulose and cellulose supports.
Benefits
designed to orient unmodified antibodies on the test line without biotinylation, to increase test sensitivity while requiring less antibody.

Gold-binding streptavidin

Attaches to
gold surfaces and gold nanoparticles.
Capture molecule
biotinylated antibodies and other biotinylated molecules.
Designed for
gold nanoparticle conjugates and gold-coated surfaces.
Benefits
designed to attach streptavidin to gold in a controlled orientation without covalent conjugation, for consistent conjugates with biotinylated capture molecules.

Gold-binding Protein G

Attaches to
gold surfaces and gold nanoparticles.
Capture molecule
antibodies (IgG), held by their Fc region.
Designed for
gold nanoparticle conjugates and gold-coated surfaces.
Benefits
designed to orient unmodified antibodies on gold without biotinylation or covalent conjugation, so more of each antibody stays active.

Polystyrene-binding streptavidin

Attaches to
polystyrene.
Capture molecule
biotinylated antibodies and other biotinylated molecules.
Designed for
plates and beads.
Benefits
designed to give controlled, uniform attachment without chemical coupling steps.

Glass-binding streptavidin

Attaches to
glass and silica.
Capture molecule
biotinylated antibodies and other biotinylated molecules.
Designed for
slides, glass supports and silica surfaces.
Benefits
designed to give direct attachment to glass without silane coupling steps.

Custom binders

The top and bottom binders can be tuned independently, so a binder for a different capture molecule or material can be developed with a partner.

For gold surfaces and particles, see GemGold.

Who uses GemChem Binders

  • Lateral flow and contract developers who want increased performance and lower cost while reducing test development time.
  • Assay manufacturers looking to reduce antibody cost of goods.
  • Developers of plate-based, bead-based and glass-based assays.
  • Materials and reagent suppliers adding a differentiated component to their portfolios.

Try a Gemina binder in your assay.

Comparative results are coming.

Side-by-side studies of the GemChem Binders are under way. We add results to this page as they are cleared for release.

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