Microinjection for Single-Cell Analysis and Therapy

Microinjection is a century-old technique which is being utilized in a wide variety of single-cell analysis as well as for intracytoplasmic sperm injection (ICSI) as one of the assisted reproductive techniques (ART) in the treatment of infertility. Microinjection is a method of transfection which involves the introduction of foreign agents/cargos into a particular cellular region, such as cytosol or nucleus, physically using microneedles. Although introduced a century ago, the direct delivery of foreign agents and biomolecules using microinjection is popularly used owing to its advantages such as precise delivery, physical means of bypassing cellular barriers, transfection of large biomolecules, low toxicity, etc.; however, this technique demands technical expertise as well as extensive instrumentation. Thus, several improved methodologies have been developed to facilitate the efficiency of output using robotic and microfluidic systems. This gold standard technique had been translated and adapted globally for the treatment of infertility and healthcare. This chapter provides basic understanding on the development of microinjection technique, pros and cons, instrumentation setup essential for microinjection, and advancements in the method via adaptation of automated robotic and microfluidic systems, as well as its inevitable role in single-cell research analysis and therapy.