Transfection is the process of introducing foreign material, such as DNA fragments, into a host cell. Microinjection and optical transfection, which is also known as laser-assisted photoporation or optoporation, are two specialized mechanical transfection techniques designed to be used with a wide array of cell types. Although similar in concept, microinjection uses a specialized pipette to inject foreign DNA directly into a cell. In contrast, optical transfection uses an optical source—most often a diode laser—to burn a transient hole in the cell membrane, allowing foreign materials to enter.

Compared with more conventional transfection methods, both microinjection and optical transfection offer a variety of advantages. Due to its direct contact with the host cell, microinjection is among the most efficient methods of transfection. However, since optical transfection does not make contact with the host cell, the cell is less likely to be damaged, increasing cell viability and decreasing toxicity.

While the respective advantages for microinjection and optical transfection are quite promising, these techniques are not without shortcomings. The biggest drawback for these methods is the throughput. Since they are mostly used with single cells, experiments are often labor intensive. Furthermore, the cost of optical transfection equipment can be significant since the technique uses expensive lasers.

Due to the novel nature of the technology, there are only a handful of vendors providing complete systems for microinjection and optical transfection. Cyntellect’s Laser-Enabled Analysis and Processing (LEAP) technology combines optical transfection and laser manipulation in one unit. In October 2011, Intrexon Corporation purchased the rights to LEAP technology to complement their products for cellular analysis (see IBO 2/15/12). French-based Imstar offers a system that combines its Pathfinder imaging platform with a UV laser to create an all-in-one system. The technology offers three modes of cellular transfection and allows users to perform time-lapse experiments.

The Neon transfection system from Life Technologies is a microinjector unit with an efficiency rate of up to 90%. The technology is based on the first-generation Microporation MP-100 system, which was commercialized by Digital Bio. XenoWorks from Sutter Instruments, microINJECTOR from TriTech Research and Nanoject II from Harvard Apparatus are three other popular microinjector units.

Microinjection and optical transfection are novel techniques within the nearly $400 million transfection market. While these technologies are efficient and less toxic than other transfection methods, their sales will grow mainly because of improvements in throughput. Furthermore, clinical applications are expected to contribute to the future prosperity of the microinjection and optical transfection markets.

Microinjection and Optical Transfection at a Glance:

Leading Suppliers

• Cyntellect

• Life Technologies

• Imstar

Largest Markets

• Academia

• Government

• Biotechnology

Instrument Cost

• $1,000–$200,000