As the saying goes, if a worker wants to do a good job, he must first sharpen his tools. The choice of consumables is very important to obtain satisfactory PCR experiment results. When analyzing PCR results, we often focus on the analysis of primers, enzyme concentration, temperature and time, but ignore that PCR consumables are also one of the influencing factors. There are many types of PCR consumables, how to choose the right PCR consumables? Here are a few questions to help you find your answer.
pcr consumables
1. Why are PCR consumables generally made of PP?
Whether it is ordinary PCR or real-time fluorescence quantitative PCR (qPCR), usually its consumables will be in direct contact with reagents or samples, so high-quality materials and good processing techniques are required in the production and preparation process. General consumables are made of polypropylene (PP). Polypropylene (PP) is a biologically inert material, the surface is not easy to adhere to biomolecules, and has good chemical resistance and temperature tolerance.
2. How to choose PCR tubes/plates with different volumes?
Common volumes for PCR tubes/plates:
• Single tube/8-tube/12-tube: 0.5mL, 0.2mL, 0.1mL
• 96-well plate: 0.2mL, 0.1mL
• 384-well plate: 0.02mL
Specifications for PCR tubes/plates:
Select the appropriate product according to the specific experimental requirements. The volume of most PCR tubes can meet the requirements of PCR reactions. The capacity specifications are available in standard capacity and low capacity. Generally, it is recommended to choose low capacity tubes first. Because the low-volume reactor tubes/plates have less headroom, heat transfer is improved and evaporation is reduced. At the same time, it is necessary to avoid adding too much or too little sample when adding samples. Too much can lead to decreased thermal conductivity, spillage and cross-contamination, while too little can cause sample evaporation loss.
3. What is the difference between the flat cover/convex cover of single tube or 8-row tube?
When the sample volume is small, single tube or 8-tube tubes are preferred. However, when the reaction volume requirement is large, single tubes prevail, and the volume can reach 0.5 mL. There are two types of single tube and 8-tube tube with flat cover and convex cover, each has its own advantages. Flat cap provides precise fluorescent signal delivery for qPCR; easy to write on markers. The convex cover is in contact with the PCR instrument cover to reduce tube deformation caused by pressure; however, it will affect the transmission of fluorescent signals and cannot be applied to qPCR experiments.
4. What are the differences in the use scenarios of different 96-well plates?
96-well plates are generally divided into non-skirted plates, semi-skirted plates, and full-skirted plates.
Skirtless plates: Compatible with most thermal cyclers or qPCR machines, but not suitable for automated applications. The stability is not high during the pipetting process, and it needs to be used with a plate holder.
Semi-skirt plate: It can be adapted to label or apply barcode, and automatic application, and has good pipetting stability.
Full skirt plate: very suitable for automated laboratory applications, but also suitable for labels and barcode applications. Good mechanical strength, suitable for PCR machines with protruding modules, and high stability during pipetting.
5. Is the PCR plate/tube material thicker and more stable?
no. PCR consumables must have a uniform wall thickness to provide consistent heat transfer. The ultra-thin tube wall is 50% thinner than the standard version, which can further reduce the thermal barrier, resulting in faster and better response.
6. For 96-well or 384-well plates, why are the cut corners and labels not the same?
Corner cutting: The choice of the corner cutting position of the PCR plate depends on the requirements of the adapted instrument for easy positioning.
Identification: Alphanumeric markings on PCR plates help identify individual wells and sample locations. Generally, it is a raised color number logo or an engraved logo. For some automated application experiments, the reaction plate with imprinted marks will be better sealed.
7. Some PCR plate wells are protruding, while others are flat. Which one is better?
What is suitable is good. Common PCR plates have two types: flat well edges and raised well edges. Reaction plate with flat well edge, suitable for most thermal cyclers. The reaction plate on the edge of the riser hole is convenient for sealing, which can reduce the risk of cross-contamination between samples.
8. How to choose PCR tubes/plates of different colors?
For ordinary PCR reactions, transparent ones can be used. In the real-time PCR reaction, the sensitivity and consistency of the white tube are relatively higher. The white tube walls prevent fluorescence from passing through the tube walls and refraction, thereby preventing the fluorescence from passing to the heating module, being absorbed by the module, or reflecting inconsistently. Compared with transparent tubes, stronger and more focused fluorescence signals can be collected at the top of white tubes.
