Microcentrifuge tubes, those tiny workhorses of the biological research lab, come in a surprising variety. Selecting the most suitable ones for your experiments requires careful consideration of several factors to ensure optimal performance and sample integrity. Here's a detailed breakdown of the crucial aspects to keep in mind when making your choice:

1. Sample Volume

• Capacity: Microtubes come in various sizes, with the most common being 1.5 mL and 2.0 mL. However, smaller options (0.2 mL, 0.5 mL) cater to applications requiring less sample volume, while larger tubes (5 mL) are available for situations needing higher volumes.
• Headspace: Always consider leaving some headspace (empty space) at the top of the tube. This allows for proper mixing without spillage during pipetting and prevents the tube from overflowing during centrifugation at high speeds.

2. Sample Compatibility

• Chemical Resistance: The tube material needs to be compatible with the chemicals you'll be using with your samples. Some solvents might react with certain plastics, leading to degradation or contamination of your samples.
• Protein Binding:For protein-based samples, consider tubes made from polyethylene (PE) which exhibit low protein binding properties. This minimizes protein loss to the tube walls, ensuring you recover a larger portion of your precious sample for analysis.

3. Centrifugation Requirements

• Speed and G-Force:Microtubes have a maximum rated speed or g-force they can withstand during centrifugation. Exceeding these limits can cause tube failure, leading to sample loss and potential safety hazards. Always choose tubes rated for speeds exceeding the forces your centrifuge will generate during your experiments.

4. Application

• Storage and Mixing: For general sample storage and mixing applications, round-bottom microtubes are a suitable choice. Their wider base allows for easier sample manipulation and mixing with pipettes.
• Pelleting:If your experiment involves separating suspended particles from a liquid (pelleting) during centrifugation, conical-bottom microtubes are ideal. The conical shape facilitates the formation of a tight pellet at the bottom of the tube, allowing for easier removal of the supernatant (liquid portion) after centrifugation.
• Sterility:For cell culture applications or experiments requiring a sterile environment, pre-sterilized microtubes are essential. These tubes undergo sterilization processes like gamma irradiation to eliminate any contaminating microorganisms.

And then I want to give you some tips for using micro centrifuge tubes effectively.