Can ordinary EP tubes be used for aliquoting and storing bioreagent AB?

It is best to divide the volume according to the amount of one experiment. For example, if the single dose is 20 μ L, divide it into 20-25 μ L portions; If the dosage is different each time, it can be divided into several specifications, such as 10, 25, or 50 μ L/tube. Fixing 10 μ L often leads to the use of multiple tubes or an increase in freeze-thaw cycles. After packaging, mark the product name, batch number, concentration, packaging date, and freeze-thaw cycles for easy traceability.

After packaging, the storage time at -20 ℃ should generally follow the instructions to avoid repeated freezing and thawing; If it is expected to be unused for more than a month, it can be stored at -80 ℃, but not all proteins are suitable for repeated freeze-thaw cycles. It is recommended to divide them directly according to a single dose during packaging. Before use, take a tube for activity validation and compare it with the undifferentiated original solution. If a decrease in potency is found after packaging, consider replacing the suction tube or adding 0.1% BSA to the diluent for protection.

Protection from light cannot rely solely on turning off the refrigerator light. It is recommended to use light-protected cryogenic vials or, after aliquoting, wrap the tube rack in aluminum foil, especially for fluorescently labeled antibodies or photosensitive reagents. Ordinary transparent EP tubes may also be affected by light during long-term storage in the refrigerator. Tube caps must be securely fastened; screw-cap cryogenic vials are preferred to prevent snap caps from loosening at low temperatures and allowing moisture to enter. Place them in cryoboxes to reduce temperature fluctuations.

For short-term cryopreservation in regular 1.5 mL EP tubes, there is generally no major issue. However, if the antibody or protein concentration is relatively low, or if downstream labeling or quantification is planned, low protein binding tubes are recommended. Adsorption to the tube wall has a relatively small effect on high-concentration stock solutions, but losses can be significant after dilution into working solutions. Aliquotting should be performed on ice whenever possible. Before aliquotting, mix gently and centrifuge briefly to avoid bubbles and uneven aliquoting.