Plastic serological pipettes are mainly used to precisely measure or transfer a certain volume of liquid, and widely applied in the fields of cell culture, bacteriology, clinic, laboratories, etc. 

1. Liquid Transfer: Designed for accurately transferring measured volumes of liquids, typically in the range of 1mL to 100mL. 

2. Cell Culture: Commonly used in cell culture applications for adding or removing media and reagents. 

3. Sample Preparation: Useful for preparing samples for assays, dilutions, and other experimental procedures. 

4. Micropipetting: Allows for precise pipetting in various experiments, ensuring consistent results.