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Molecular Probes™ Bacteria Counting Kit, for flow cytometry
Description
The Bacteria Counting Kit accurately enumerates bacteria by flow cytometry. The kit includes the SYTO™ BC dye, which is also available separately (Cat No. S34855), a high-affinity nucleic acid stain that easily penetrates both gram-negative and gram-positive bacteria, producing an exceptionally bright green-fluorescent signal. The kit also includes a calibrated suspension of polystyrene microspheres. Signals from both the stained bacteria and the beads are easily detected in the green fluorescence channel and can be distinguished on a plot of forward scatter versus fluorescence. The density of the bacteria in the sample can be determined from the ratio of bacterial signals to microsphere signals in the cytogram.
Any physiological buffer between pH 7.0–8.0, including PBS, can be used to dilute the SYTO dyes for the staining solution.
Specifications
Specifications
| Product Type | Bacteria Counting Kit |
| Detection Method | Fluorescence |
| Quantity | 1 kit |
| Sample Type | Bacteria |
| Diameter (Metric) Bead | 6 μm |
| Content And Storage | Contains 1 vial of SYTO™ BC bacterial stain (100 μL, 1000x in DMSO), 1 vial microsphere standard (1 mL, 6 μm). Store in refrigerator (2–8°C) and protect from light. |
| For Use With (Application) | Flow Cytometry |
| For Use With (Equipment) | Flow Cytometer |
| Includes | BC Bacterial Stain, Microsphere Standard |
| Shipping Condition | Room Temperature |
Frequently Asked Questions (FAQs)
Yes, the SYTO BC bacteria stain can be purchased separately (Cat. No. S34855).
The green dye in the kit will label all the cells as it is a cell-permeant nucleic acid stain. The red dye is not cell permeant, and will only stain the cells with compromised membranes (dead cells). Therefore, any cells with red signal will be considered dead. It is possible that you will have some cells that are only red, some that are red and green, and some that are only green. Sometimes the red dye will displace the green dye. In any case, any red cells are dead.
Also, the green dye emission may bleed through into the red channel. Do a single-color staining and examine under both green and red filter sets to determine the level of bleedthrough. To avoid this bleedthrough, use a lower concentration of dye, and, if possible, use narrow bandpass filters.
There are several options. We have two fluorescence based kits that are useful for bacterial counting: Live/Dead BacLight Bacterial Viability and Counting Kit, for flow cytometry (Cat. No. L34856) and Bacteria Counting kit, for flow cytometry (Cat. No. B7277). Another option is the Flow Cytometry Sub-micron Particle Size Reference Kit (Cat. No. F13839).
You can stain bacteria with a general stain such as BacLight Green Bacterial Stain (Cat. No. B35000) or BacLight Red Bacterial Stain (Cat. No. B35001). You can look at gram character (Cat. No. L7005), cell viability (Cat. Nos. L7007, L7012, and L13152), cell count (Cat. Nos. L34856 and B7277), and cell vitality. Cell vitality can be measured by membrane potential (Cat. No. B34950) or by metabolism (Cat. Nos. B34954 and B34956).
The first thing to do is check your threshold and see if it is set on forward scatter. If so, the beads are probably being excluded by the threshold. Reducing the threshold setting should reveal your beads.
For Research Use Only. Not for use in diagnostic procedures.