Related Product Information
Principle of Release
Release of Dynabeads® from the cells using DETACHaBEAD® provides a fast and reliable method of positive isolation. The cells may be isolated from mouse spleen, thymus or lymph nodes using Dynabeads® Mouse CD4 (L3T4) (not included). DETACHaBEAD® Mouse CD4 is then added to the bead-bound cells and will release the Dynabeads® and primary antibody from the mouse CD4+ T cells. Following a short incubation period, the released Dynabeads® are removed by magnetic separation and the positively selected cells collected. The isolated cells are pure (>99%), viable (>95%) and are not activated by the isolation or release procedure.
The isolated cells are pure, viable and are free from antibody bound to the surface. The isolated cells can be use for any research applications, functional studies and flow cytometry. Cells positively isolated and released in this way have been shown to respond in a normal manner when stimulated with interleukin-2 or interferon-gamma.
Description of Materials
DETACHaBEAD® Mouse CD4 is a polyclonal antibody specifically made to out-compete the binding of mouse CD4+ cells to the Dynabeads® Mouse CD4 (L3T4) (not included). The product contains 5 ml of DETACHaBEAD®, supplied in 0.15 M phosphate buffered saline (PBS) pH 7.4. 1 ml of DETACHaBEAD® is sufficient to release cells from 2 ml Dynabeads® Mouse CD4 (L3T4).
Additional Materials Required
Materials that are not included, but are needed to perform the entire protocol:
- Dynabeads® Mouse CD4 (L3T4), (Cat. no. 114.45D) for positive isolation of mouse CD4+ cells.
- Magnet: See www.invitrogen.com/magnets for magnet recommendations.
- Mixer allowing both tilting and rotation.
- Tubes: We recommend adapting the tube size to the working volume (e.g. using 1.5 ml Eppendorf tubes for small volumes).
- Cell culture media: RPMI 1640/1% FCS (Foetal Calf Serum).
- Never resuspend the positively isolated cells in less than 100 μl Cell culture media, even if the starting sample is less than 1 x 107 MNC or 1 ml blood.
- The volume of DETACHaBEAD® used relates to the volume of Dynabeads® used for cell isolation. Never use less than 10 μl DETACHaBEAD® per 25 μl Dynabeads® used for positive isolation. The amount of DETACHaBEAD® used can be directly scaled up.
- Incubation at 2-8°C will significantly reduce the number of released cells. Incubating at 37°C will not increase release efficiency.
- Perform positive cell isolation with Dynabeads® Mouse CD4 (L3T4) as recommended (for protocol, see package insert for Dynabeads® Mouse CD4 (L3T4), (Cat. no. 114.45D). Resuspend the bead-bound cells in 100 μl Cell culture media.
- Add 10 μl DETACHaBEAD per 25 μl (1 x 107) Dynabeads® used to isolate the bead-bound cells in the positive isolation protocol.
- Incubate for 45 min at room temperature with gentle mixing.
- Place the tube in a magnet for 1 min.
- Transfer the supernatant containing released cells to a fresh tube. To obtain residual cells, wash the beads 2-3 times in 500 μl Cell culture media and collect the supernatant.
- Wash released cells thoroughly by resuspending the cells in a total volume of 10 ml Cell culture media and centrifuge for 6 min at 400 x g to remove DETACHaBEAD®.
- Resuspend the cells in Cell culture media or other media and use in downstream application.
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