Microinjection is a laboratory technique used to introduce substances, such as DNA or proteins, directly into individual cells. This method involves using a fine glass needle to inject the desired material, allowing for precise control over the amount and location of the injection. Microinjection is commonly used in genetic engineering and developmental biology to study cellular processes and create genetically modified organisms. This technique is particularly important in the field of transgenic research, where scientists create organisms with altered genetic material. Microinjection can also be applied in fertilization processes, such as in vitro fertilization, to enhance the success rates of embryo development.