Project summary: High-throughput Single Cell Screening Using a MEMS Assay

Within this project we want to take the first steps towards an automated system for high-throughput single cell based screening in the production of novel biopharmaceuticals using a new MEMS array technology which allows for single cell read-out.

The current sales of biotherapeutics in the biopharmaceutical industry is close to US$125 billion. The amount of new cell line development projects for drug production purposes is still growing rapidly mainly due to the expiration of blockbuster biologics which has spurred the emergence of biosimilars. Mammalian cells have been utilized for a long time in the production of biopharmaceuticals. Currently cell handling is executed at the colony level (single-colony-based-breeding). However, these colonies are highly heterogeneous in nature due to the gene amplification process and random gene integration. As a result, production rates amongst different cells in a colony varies greatly. This implies that large numbers of clones have to be screened to identify the rare stable high producer cell clones. Consequently, the current cell line development processes are extremely time, labour and capital intensive.

High-producing cell lines could be established much more effectively by sorting single cells (as opposed to colonies), with high and stable expression rates, early in the production process. Microwell array technology, whereby each microwell occupies a single cell, has been suggested as a means for high-throughput screening of large numbers of individual cells. The bottleneck which currently hampers microwell array technology from entering the market successfully is the lack of an efficient and sensitive single cell read-out system.

In the current project a MEMS microarray will be developed containing a read-out pore (or read-out pores) in the bottom of each well in the array. These pores will allow stamping of products (such as antibodies) secreted by individual cells on a substrate such as paper, pvdf, other. Subsequently, read-out will be performed using for example ELISA technology and/or fluorescently labelled antibodies.

The major advantage of this approach is that the readout system does not interfere in any way with the cells in the wells of the array. Moreover, due to the sensitivity of the immunological read-out it is expected to be fast. Other advantages include that the read-out methodology is highly selective (allowing discrimination between antibody isotypes and/or subclasses), high throughput, quantitative, cheap, simple and compatible with current workflows in the field.

Applications

Most CFM applications can be grouped into two main categories:

  • Surface analysis and characterization
  • Binding – unbinding events

CFM measurement conditions can be tuned in terms of solvent, temperature and pH. Biological samples can be measured under physiological conditions.

 

Types of applications:

  • Measurement hydrophilic/hydrophobic interactions
  • Intermolecular force measurements
  • Chemical sensing and detection
  • Local mapping of functional group distributions or receptors
  • Local mapping of surface properties (e.g. modulus)

Application examples in different areas:

  • Polymers (determination composites/blends/phase separation/microstructure)
  • Biomaterials (implants, bio-sensors, dental enamel structure)
  • Tribology (friction, wear)
  • Cosmetics (hair, development shampoos/conditioners, skin, contact lenses)
  • Pharmaceutical industry (study of membrane proteins for development of new drugs)

Chemical SPM Probes

SmartTip has recognised the growing demand for chemically activated probes for Chemical Force Microscopy (CFM) and has recently added chemical probes to its probe portfolio.

Applications

A list of applications for CFM is placed here.

SmartPack

The reliability and reproducibility of a CFM measurement strongly depends on the quality of the chemical probe. With this in mind we developed a special packaging concept for chemical propes: SmartPack.

SmartPack is unique since it is the only adequate packaging solution currently available in the market that allows for safe packaging, storing and shipping of chemical probes.

More information about SmartPack is located here.

CFM probe types

A description of available probe types is located here.

Benefits:

  • Off-the-shelf availability
  • SmartPack ensures high quality chemical probes
  • Variety of different chemical probes available
  • Custom modifications are possible
  • Excellent technical support and high customer service

SmartPack

SmartPack prevents surface contamination, oxidative degradation and/or physical tip damage and ensures the highest quality CFM probes at all times. Additionally, SmartPack also allows for off-the-shelve availability (several months) of your functionalized probes.

 

The SmartPack consists of a holder submerged in a tube containing a special solution which has been optimized for a variety of different functional groups.

 

CFM Probe types

CFM probes are prepared from commercially available AFM probes which are modified with specific functional groups using self-assembled monolayer’s of thiols on gold. Thiol-Au chemistry offers several advantages over alternative modification protocols:

  • Well-defined chemistry
  • Very organized and stable SAMs
  • Highly reproducible functionalization (robust production process)
  • Extremely versatile (many different chemical functionalities)

Custom modifications and/or functionalization of probes provided by clients are often possible. Please do not hesitate to contact us with specific requests and/or questions.