Frequently Asked Questions - Answers to Reagent Product Issues-He Yuan Li Ji

Q：What tests is the ROS detection kit suitable for?

It is generally used for the detection of mammalian cells and is only suitable for the detection of reactive oxygen species in live cells or living organisms.
Q：Is the ROS detection kit suitable for detection in serum or plasma?

Not suitable for detecting ROS in serum or tissue homogenates. Fresh tissue prepared single-cell suspension can be attempted.
Q：What are the reasons and solutions for FITC staining failure?

1. The cell clusters did not separate. Solution: It is recommended to set the centrifugal force at 500-1000g. If the centrifugal force is too low, only normal cells will be collected, and apoptotic cells and fragments will be lost, resulting in a low apoptosis rate; 2. No single staining control was conducted. Solution: The fluorescence value and background of each reagent kit are different, and the position of the cross door is also different. For example, compared to Li Ji, domestic American brands tend to lean to the left, while domestic brands tend to lean to the right. Therefore, it is recommended that customers do single dye door marking; 3. Too many cells. Solution: If there is no signal in the picture, it means that it was not detected, which means the signal exceeds the detection range. It is recommended to set the parameter to 10000 cells; 4. FITC cannot be stained. Solution: Generally, freezing will have an impact on FITC, and Li Ji's product recommendation is not to freeze it; 5. The concentration and duration of dye exposure, as well as incubation conditions, are also the main factors affecting staining. Solution: Different cells may not be exactly the same, and there are optimal conditions that need to be explored and confirmed. 6. Insufficient stimulation of cell apoptosis itself. Solution: Adjust the duration and concentration of drug action. 7. The state of the cell itself, such as cells that proliferate excessively and are insensitive to apoptotic stimuli. Solution: Confirm the cell state. 8. The digestion time of adherent cells is too long, the PS on the membrane surface is damaged, and the number of Annexin V binding sites decreases. Solution: Adjust the cell digestion time and avoid excessive digestion
Q：Do I need to pack and store lentivirus cryovials when using them?

To avoid repeated freezing and thawing of the same virus, which may cause a decrease in titer, it is recommended to pack it separately when using it. During the packaging process, it is necessary to ensure that the operation is carried out in a sterile environment on ice. The packaging volume should be based on the amount of virus used in each experiment, and should not be too small. It is recommended to not be less than 10uL. If the virus after packaging is used for a short period of time, it can be temporarily stored at 4 ℃ (used up within a week). The remaining virus should be stored at -80 ℃ immediately after packaging.
Q：What is the sensitivity of Li Ji's Coomassie Brilliant Blue rapid staining solution?

The sensitivity reaches nanogram level (0.4ng), and a large amount of experimental data shows that this dye solution can color the protein on the gel within 2 minutes, with extremely high sensitivity.
Q：Why is decolorization no longer necessary when using Li Ji Coomassie Brilliant Blue rapid staining solution?

After running the glue, the protein adheres to the glue. If traditional staining solution is used, the entire gel will be stained when staining the protein, so it is necessary to wash off the staining solution on the gel background. Using Li Ji Kaoma, it has strong specificity and only stains proteins, without staining gel, so there is no need for further decolorization.
Q：What are the concentrations of 1xPBS and 10xPBS for Li Ji Biology?

The working concentration of 1xPBS is 0.01M (molar concentration), and the working concentration of 10xPBS is 0.1M (molar concentration)
Q：Do we need to make a standard curve every time we use CCK-8 to measure cell viability?

Suggest doing it every time. Although cells are the same, their states may not necessarily be the same. For cells with different states, it is recommended to perform a standard curve every time.
Q：Is the sensitivity of CCK-8 the same for different cells?

dissimilarity. Suspended cells are more difficult to stain than adherent cells. For adherent cells, the absorbance is generally high after 1-4 hours of cultivation with CCK-8, but for suspended cells, the absorbance may be low. This can be solved by extending the addition time of CCK-8 or increasing the number of cells.
Q：Does the drug affect the determination of CCK-8 during cell drug addition experiments?

1. Note that if the drug has reducing properties (such as vitamin C), it will undergo a color reaction with CCK-8, increasing the absorbance. 2. The metals in the drug have an impact on the color development of CCK-8: when the final concentration is 1mM, lead chloride, iron oxide, and copper sulfate will inhibit 5%, 15%, and 90% of the color development reaction, resulting in a decrease in sensitivity. If the final concentration is 10mM, it will be 100% inhibited. Solution: Firstly, it is necessary to confirm whether the drug has been absorbed. Add CCK-8 to the culture medium containing the drug and measure the absorbance at 450nm. If its absorbance is higher than that of the culture medium without the drug (with CCK-8 added), it indicates that the drug has an effect. The culture medium can be changed before adding CCK-8 to remove the effect of the drug. 3. Due to the possibility of oxidation-reduction reaction substances in the culture medium, it is recommended to use a well for testing before the formal experiment. It is necessary to confirm whether the culture medium and CCK-8 react first. Generally, the normal OD value should be below 0.4.

1 2 3 4 5 6 7 8 9 10 ... 13 14

go to page