What factors affect the extraction results of an automatic nucleic acid extractor?

The following are some of the factors that can affect the extraction results of an automated nucleic acid extractor:
Sample-related factors
Sample type and quality: Different types of samples, such as blood, tissues, saliva, feces, etc., differ greatly in their cellular structures and compositions, and have different lysis difficulties. For example, plant tissues have cell walls, which are more difficult to lyse and require more intense lysis conditions; the presence of clots in blood samples will affect the lysis effect and nucleic acid release.
Sample size: Too much or too little sample size is not favorable for extraction. Too much sample volume may exceed the capacity of the lysis solution and reagents, resulting in insufficient lysis and impurity residues; too little sample volume will result in low nucleic acid yield, which is difficult to meet the needs of subsequent experiments.
Reagent factors
Lysate: The composition, concentration and quality of lysate are crucial for nucleic acid extraction. The ratio of guanidine salt, surfactant and other components will affect the cell lysis efficiency and nucleic acid stability. High concentrations of guanidinium salts may enhance lysis, but may also affect the integrity of nucleic acids.
Binding Buffer: The nature and concentration of the binding buffer affects the ability of magnetic beads or other adsorption carriers to adsorb nucleic acids. Inappropriate binding buffers can lead to incomplete adsorption of nucleic acids and reduce extraction efficiency.
Wash buffer: Wash buffer is used to remove impurities. If its formulation is poor or its quality is questionable, it may not be able to effectively remove impurities such as proteins, salt ions, etc., thus affecting the purity of nucleic acids.
Elution solution: The type, concentration and volume of the elution solution, as well as the elution temperature and time, all affect the elution efficiency of nucleic acids. If the eluent is not suitable and the temperature and time are not appropriate, it is difficult to elute nucleic acids from the adsorbent carrier, resulting in a lower yield.
Instrument performance and parameter setting
Temperature control: The lysis and elution steps in the nucleic acid extraction process have strict temperature requirements. Inaccurate or uneven temperature will affect the lysis efficiency, binding and elution of nucleic acid and adsorbent carrier, and then affect the extraction effect. For example, too high a lysis temperature or too long a time may cause nucleic acid breakage; too high an elution temperature may lead to nucleic acid degradation.
Magnetic rod performance: For the magnetic bead method extractor, the magnetic strength, oscillation amplitude and mixing time of the magnetic rod are parameters that directly affect the adsorption of magnetic beads, washing and release of nucleic acids. If the magnetic strength of the magnetic rod is weak, the nucleic acid adsorbed by the magnetic beads will be incomplete; if the oscillation amplitude is too small or the mixing time is too short, there will be many impurities left; if the oscillation amplitude is too strong or the mixing time is too long, nucleic acid will be easily broken and lost.
Accuracy and reproducibility of sampling: Poor accuracy and reproducibility of sampling in the extractor with sampling function will lead to inaccurate addition of reagents, which will affect the effect of lysis, binding, washing and elution, and ultimately affect the consistency and quality of nucleic acid extraction.
Operation and environmental factors
Operation standardization: If the operator does not follow the standard operation procedures for sample treatment, reagent addition, instrument operation, etc., such as improper sample pretreatment, wrong order of reagent addition, or untimely cleaning and maintenance of the instrument, impurities may be introduced, which may affect the performance of the instrument and reduce the extraction effect.
Environmental conditions: The temperature, humidity and cleanliness of the environment in which the instrument is located also have an impact. Too high or too low temperature and too high humidity may affect the performance of the electronic components of the instrument and the stability of the reagents; unclean environment, dust and other pollutants into the instrument or the sample will lead to contamination of nucleic acids, affecting the quality of extraction.
Quality of consumables
Adsorption columns or magnetic beads: Different brands and models of adsorption columns or magnetic beads have different nucleic acid adsorption capacity and impurity removal effect. Poor quality adsorption columns or magnetic beads may not be able to effectively adsorb nucleic acids or remove impurities, affecting the extraction effect and purity of nucleic acids.
Centrifuge tubes and pipette tips: If the quality of centrifuge tubes and pipette tips are not up to standard, there may be problems such as residual impurities and adsorption of nucleic acids, which may lead to cross-contamination of samples and loss of nucleic acids, affecting the accuracy and reliability of extraction.