Dye Handling and Storage of Dye Labeled Probes
Labeled probes are shipped dry and can be stored frozen in this state indefinitely. Here are general guidelines for handling and storing probes along with other helpful information.
Dye Labeled Probes
Probes are best prepared for use and long-term storage by first preparing concentrated stock and diluting the working solution of the probe.
- Re-suspend the dry oligo in aqueous or buffered solution to a known stock concentration. Prepare a 100 µM stock solution of oligo using the “Total nmol” value of the dry probe on the Certificate of Analysis that ships with every probe. Multiply by 10 to determine the volume of diluent in microliters to add.
- Dilute a portion of the stock solution to an appropriate working concentration, aliquot into microvials and store all at -20°C or -80°C.
PROBES SHOULD BE SUBJECTED TO A MINIMUM NUMBER OF FREEZE-THAW CYCLES
Prepare the stock and working solutions using one of the following:
- TE Buffer (10 nM Tris-Cl/1 mMEDTA). pH 8.0 (Recommended)
- DNase-free water
The pH of Tris buffers changes significantly with temperature, decreasing approximately 0.028 pH units per 1°C rise in temperature. Tris-buffered solutions should be adjusted to the desired pH at the temperature at which they will be used. Because the pKa of Tris is 8.08, Tris should not be used as a buffer below pH -7.2 or above pH -9.0
Short-term Storage & Daily Use
Probes should be subjected to a minimum number of freeze-thaw cycles. Therefore, we recommend that you prepare and store microvials each having sufficient material for a day’s set of experiments and freeze at -20°C or -80°C.
When ready to use, bring a sufficient number of aliquots out of the freezer and hold in an ice bucket with a lid to minimize exposure to light until ready for use.
We recommend freezing probes either at -20°C or -80°C. Probes and primers can be stored in this state for over one year.
Protection from Photobleaching
To ensure optimum activity, fluorescent probes should always be protected from light to avoid photobleaching.
If you require additional information or technical assistance, please feel free to email our Technical Support group at firstname.lastname@example.org.
For immediate assistance, our scientific staff is available for telephone consultation from 8:00 AM to 5:00 PM, Monday through Friday central standard time.
Please contact us at:
1.800.227.0627 U.S./Canada only