Pasteur pipettes are slender, glass or plastic pipettes commonly used in laboratories for transferring small volumes of liquids. Named after Louis Pasteur, they are designed with a narrow stem and a bulb at the top, allowing for precise control when drawing and dispensing fluids. Often used for delicate tasks like adding reagents or transferring biological samples, Pasteur pipettes are disposable and non-graduated, making them ideal for one-time use to prevent cross-contamination. They are widely used in various lab settings, from chemistry to biology, due to their simplicity and reliability.