Cytodiagnostics is a biotechnology company based in Burlington, Ontario, Canada. Their focus is providing and developing nanotechnology derived products and services for the international life science and material science markets.

Their life science portfolio contains products and services specifically tailored for in vitro and in vivo assay development and research including:
Gold and Silver Nanoparticles
Magnetic Nanoparticles
Polystyrene Beads
Application Specific Assays & Support Reagents

Product Categories  

Gold Nanoparticle 

  • Spherical Gold Nanoparticles
  • Gold NanoUrchins
  • Gold Nanorods
  • Gold Nanoparticle Conjugation
  • Gold Conjugates
  • Functionalized and Pegylated Gold
  • Nanoparticles
  • Organic Soluble Gold
  • Nanoparticles
  • Gold Nanoparticle Size
  • Optimization Panels
  • Gold Nanoparticles for Flow
  • Cytometry

 Silver Nanoparticles

  • Standard Silver Nanoparticles
  • Reactant Free Silver Nanoparticles
  • Silver Nanoparticle Size
  • Optimization Panels
  • Silver Nanoparticle Conjugation
  • Silver Conjugates
  • PEGylated Silver Nanoparticles

Polymer Microspheres

  • Fluorescent Microspheres
  • Magnetic Microspheres

Magnetic Nanoparticles

  • Iron Oxide Nanoparticles
  • Magnetic Microspheres

Gold Silver Alloy Nanoparticles

  • Gold Silver Alloy Nanoparticles (Standard)
  • Gold Silver Alloy Nanoparticle Conjugates

 Fluorescent Nanocrystals

  • Fluorescent Nanocrystals – Alkyl
  • Fluorescent Nanocrystals – Amine
  • Fluorescent Nanocrystals –
  • Carboxy
  • 450nm emission
  • 490nm emission
  • 525nm emission
  • 540nm emission
  • 575nm emission
  • 630nm emission
  • 665nm emission

Nanoparticle Purification and Sample Preparation

Nanoparticle Optimization Panels

  • Fluorescent Nanocrystal Optimization Panels
  • Gold Nanoparticle Optimization Panels
  • Silver Nanoparticle Optimization Panels and Kits

Western Blot and Immunoblotting Products

  • Multiplex Detection Kits for Western Blot
  • Secondary Nanoparticle Conjugates
  • Nanoparticle Conjugation Kits
  • Membrane Staining and Enhancement Kits

Rapid Test Development Kits


Flow Cytometry

  • Fluorescent Microspheres
  • Size Standards for Flow Cytometry


Our Four Simple Missions

Our main goal is product innovation and satisfaction – We aim to ensure that the exact products you requested are delivered to you in the quickest possible manner. As fellow scientists, we are ensuring that products are subject to environmentally-friendly manufacturing techniques, rigorous quality control and continuous shelf-life and stability testing, all to guarantee the highest quality products.

Custom R&D – Research and Development is a significant portion of our business. Email us at tech_support[at] with your custom product or project request. Our knowledgeable team will be able to provide you with a highly competitive quote with realistic turnaround times for your consideration.

World-Wide Distribution – We fully understand that some countries have strict regulations on the import and export of nanomaterials, meaning that getting high quality materials can be a significant challenge. Our method of tackling this issue is by expanding our global distribution network to increase access to our superior quality products.

Collaborations – As engaged scientists, we strongly believe in the power of collaboration. Our end goals overlap with yours: the pursuit of scientific advancement. We welcome the opportunity to work with you on revolutionary projects no matter the scope. Nothing is too small or too large. For complicated projects, we can harness our expansive local and global academic network to develop solutions.

Cytodiagnostics is a biotechnology company based in Burlington, Ontario, Canada. Their focus is providing and developing nanotechnology derived products and services for the International Life Science and Material Science markets.

Cytodiagnostics Life Science portfolio contains products and services specifically tailored for in vitro and in vivo assay development and research including:


Gold Nanoparticles

How do I wash my gold nanoparticles?

For most applications our gold nanoparticles can be used without any additional washing steps. If you have a sensitive application that requires additional washing the best way to do so is by either centrifugation or filtration. For recommended centrifugation speeds and times please refer to Storage & Handling of gold nanoparticles – Tech Note #101.

What gold nanoparticle size should I choose for my application?

The size and the surface chemistry of gold nanoparticle to use is very dependent upon the intended application. Please see our Gold Nanoparticle Product Selection Guide to find the most optimal product for your particular application.

My gold nanoparticle settle out of solution upon storage. Is this normal?

Settling of gold nanoparticles on the bottom of the storage flask is completely normal and is especially common for larger sized particles, which settle at a greater speed. Settling does not affect the performance of the particles. Prior to use, simply swirl the solution to properly disperse your gold nanoparticles and generate a homogenous solution.

What is the shelf life of gold nanoparticles?

Our standard gold nanoparticles are stable for at least 1 year if stored unopened and as specified at 4 degrees Celsius. Do NOT store our non-functionalized standard gold nanoparticles in the freezer since this cause irreversible aggregation, see our gold nanoparticles handling and storage tech note.

The gold nanoparticle solution turns violet when I add salt containing buffer. Why is that?

Due to repulsive forces arising from the surface charge of gold nanoparticles, an energy barrier must be overcome for individual particles to interact. When no (or small) amounts of electrolytes such as NaCl are present, this energy barrier is too strong for interaction to occur between particles. However, upon addition of NaCl this energy barrier is reduced allowing the gold nanoparticles to interact and aggregate. This aggregation causes a phenomenon called surface-plasmon coupling which changes the adsorption maximum of light to a higher wavelength resulting in a change in color of the solution.

What happens if I accidentally freeze my non-functionalized gold nanoparticles?

Freezing of our non-functionalized gold nanoparticles causes irreversible aggregation and can be observed by a clear change in color of the solution, see our gold nanoparticles handling and storage tech note for more information and examples.

Fluorescent Nanocrystals (Quantum Dots)

The amount of your fluorescent nanocrystals are given in mg. How many particles does this correspond to?

The number of nanocrystals per mg is 1.2×1015.

What is the molecular weight of your quantum dots?

All of our quantum dots have the same size with a molecular weight of 650,000 Da.

What is the quantum efficiency of your quantum dots?

The quantum efficiency of our quantum dots is 55-65% (alkyl functional fluorescent nanocrystals compared to laser dyes). Our water soluble quantum dots have 15% lower quantum efficiency compared to the alkylated fluorescent nanocrystals.

First for Antibodies

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Gold Nanoparticle Handling and Storage

Storage Store product away from direct sunlight at 4-25°C. Lower temperature prolongs the shelf life of the product. Do NOT Read More…

Silver Nanoparticle Handling and Storage

  Storage Store silver nanoparticles at 2-8°C and protected from light. Do NOT freeze. If frozen, the silver nanoparticles will Read More…

Conjugation of Proteins to Zepto Ultra Express Fluorescent Microspheres

Zepto™ Ultra Express Microspheres are metal-coated fluorescent polystyrene beads designed for fast surface functionalization with molecules containing primary amines, tiol Read More…

Covalent Conjugation of Proteins to Carboxylated Gold Nanoparticles

Background Gold nanoparticle conjugates have been widely used in biological research and biosensing applications. For example, gold nanoparticles can function Read More…

Conjugation of Proteins to Silver Nanoparticles

Background Silver nanoparticle conjugates are useful for a wide range of biological applications including bio-sensing and bio-imaging. Stable silver nanoparticle Read More…

Introduction to Gold Nanoparticle Characterisation

Background Gold nanoparticles present distinct optical and physical properties, which are dependent upon their size (diameter), shape, surface structure and Read More…

Cytodiagnostics vs Leading Competitor

Colloidal gold is a versatile nanomaterial that has been used as an essential component in many biomedical applications, from diagnostic Read More…

Silver Nanoparticle Properties

Introduction Silver nanoparticles (colloidal silver) have unique optical, electronic, and antibacterial properties, and are widely used in areas such as Read More…

Gold Nanoparticle Properties

Background Gold nanoparticles (colloidial gold) have been extensively used for applications both in biology (e.g. bio-imaging) and technology (e.g. photonics) Read More…

Lateral Flow Immunoassays

While rapid assay methods have made a major impact on a variety of diagnostic testing over the last twenty years Read More…

Vertical Flow Immunoassays

Background Vertical flow immunoassays rely on the same basic principles as the more common lateral flow immunoassay format with some Read More…

Sharper Emission Peaks

Fluorescent Nanocrystals

Their range of semiconductor grade fluorescent nanocrystals/quantum dots  has the potential to be used in numerous applications in the field Read More…