Pipette tips are commonly used consumables in laboratories and have important applications in various experimental operations:

1. Molecular Biology Experiments

• Nucleic Acid Extraction and Purification
  • During the extraction of DNA or RNA from cells or tissues, pipette tips are used to accurately aspirate and transfer various reagents. For example, when using the phenol – chloroform method to extract DNA, pipette tips are needed to aspirate organic solvents such as phenol and chloroform. These organic solvents are used to remove impurities like proteins, and the pipette tips ensure safe and precise operation.
  • In the nucleic acid purification step, such as using the silica – membrane spin – column method, pipette tips are used to aspirate the elution buffer to elute the pure nucleic acid adsorbed on the silica membrane. Eventually, a high – purity nucleic acid sample is obtained for subsequent experiments, such as gene cloning, PCR amplification, etc.
• PCR (Polymerase Chain Reaction) and Related Experiments
  • They are used to prepare the PCR reaction system. Experimenters use pipettes and pipette tips to add reagents such as Taq enzyme, dNTPs (deoxynucleoside triphosphates), primers, template DNA, and buffer into the reaction tube in precise proportions. For example, in a 20 – μL PCR reaction system, 10 μL of 2× reaction buffer needs to be added, and a suitable pipette tip is required to accurately aspirate the corresponding volume of the reagent.
  • In qPCR (quantitative real – time PCR) experiments, pipette tips are also used to add samples and reagents. Moreover, in some fluorescence – based quantitative detection systems, the material of the pipette tips is highly required to avoid self – fluorescence interference, ensuring the accuracy of the detection results.
• Gene Cloning and Vector Construction
  • In the process of gene cloning, pipette tips are used to aspirate key reagents such as restriction endonucleases and ligases. These enzymes are used to cut and ligate DNA fragments to construct recombinant DNA molecules. For example, when inserting a target gene into a vector (such as a plasmid), pipette tips are used to aspirate an appropriate amount of restriction endonucleases to digest the target gene and the vector, and then pipette tips are used to aspirate T4 ligase to ligate them together. The accuracy of the pipette tips is crucial for the success of the experiment.

2. Cell Biology Experiments

• Cell Culture
  • They are used to aspirate cell culture medium. During cell culture, the culture medium needs to be replaced regularly to maintain the growth environment of the cells. Pipette tips can accurately aspirate the old culture medium, and when adding new medium, they can also ensure the accurate volume, avoiding adverse effects on cell growth caused by excessive or insufficient medium.
  • They are used for cell sub – culturing operations. When cells grow to a certain density, sub – culturing is required. Pipette tips can aspirate trypsin and other digestive fluids to detach cells from the culture flask wall, and then aspirate the cell suspension and transfer it to a new culture container for the expansion of cell culture.
• Cell Counting and Viability Detection
  • When using a hemocytometer or an automatic cell counter for cell counting, pipette tips are used to aspirate the cell suspension and evenly drop it onto the counting chamber or into the detection well of the counter. At the same time, when detecting cell viability (such as using the trypan blue staining method), pipette tips are used to aspirate the stained cell suspension to distinguish live cells from dead cells. Accurate aspiration operations can ensure the reliability of cell counting and viability detection results.

3. Biochemistry Experiments

• Protein Extraction and Purification
  • They are used to aspirate cell lysate to break cells and release proteins. For example, when using RIPA lysis buffer to extract total proteins from cells, pipette tips are used to add the lysis buffer to the cell pellet, and then aspirate the supernatant of the cell lysate containing proteins for subsequent protein purification steps, such as purifying proteins through affinity chromatography, ion – exchange chromatography, etc.
  • In protein quantification experiments (such as the Bradford method or BCA method), pipette tips are used to aspirate protein standards and test samples, and add them to the reaction system for quantitative analysis. Accurate aspiration volume is essential for obtaining accurate protein concentrations.
• Enzyme Experiments
  • In the study of enzyme activity and kinetic properties, pipette tips are used to aspirate enzyme solutions and substrate solutions. For example, when detecting amylase activity, pipette tips are needed to aspirate a certain concentration of amylase solution and starch substrate solution, mix them, and react under appropriate temperature and pH conditions. Then, the activity of the enzyme is evaluated by detecting the production of reaction products (such as glucose). The precision of pipette tips can ensure the accuracy of experimental conditions.