Hi,
I am planning to use Cholera Toxin B for neuroanatomical tracing.
The CTB conjugated with Alexa Fluor dyes can be obtained in the solid (500 ug or 100 ug powder) form from suppliers and, according to it’s product sheet information, it can be stored in the solid form at -20C for 6 months or in the solution form (after adding PBS) for 1 week.
On this protocol paper (Article Multiple neuroanatomical tract-tracing using fluorescent Ale...
) , it’s mentioned that the solution form should not be frozen as this will cause reliability problems as crystals formed during the freezing will interfere with how it is taken up by the cells; they recommend instead to aliquot the powder form into aliquots but I am finding it difficult to measure such small amounts (less than 500 ug or 100 ug) reliably,The product sheet information says that it can be stored in the fridge for longer if Sodium Azide is added, however, as this is toxic, I am afraid it might killed the neurons I am trying to label and interfere with the results.
Has anyone used Sodium Azide for storage of CTB and then used it in intracranial injections? Or does anyone as any other suggestions regarding how to handle/store CTB?
Thanks!
This comes a little late, but I've had no problem freezing Ctxb in PBS at 1 mg/mL. I will admit I didn't do thorough controls to see if freezing affects staining patterns, but I didn't notice a change and it seems a standard process others take for granted. I have also stored stained samples in PBS with sodium azide without problems in imaging after, for what it's worth.
- Badges
- Science topic
- Similar topics
- Chemistry
- Biochemistry
- Biochemical Techniques
- Blotting Techniques
- Immunoblotting
- Dyes