PCR tubes come in various sizes, but the most common dimensions are:
1. **0.2 mL Tubes**: These are the standard size for most PCR reactions and are designed to fit into standard PCR thermal cycler blocks. They are typically used for individual reaction volumes ranging from 10 µL to 50 µL.
2. **0.5 mL Tubes**: Slightly larger than 0.2 mL tubes, these are used for reactions that require larger volumes, typically ranging from 50 µL to 100 µL.
3. **1.5 mL Tubes**: These are less common for PCR but can be used for applications requiring larger volumes or for sample storage. They hold up to 1.5 mL of liquid.
4. **2.0 mL Tubes**: These are used in some specialized PCR applications or for sample storage and handling, holding up to 2.0 mL of liquid.
The tubes are usually cylindrical and designed to fit into the wells of a PCR thermal cycler block, which is often configured to accommodate the 0.2 mL size. Some PCR tubes also have conical bottoms to help concentrate the reaction mixture at the bottom of the tube.
