Q: I am doing retrograde neuronal labeling using the NeuroTrace DiI Paste. I apply a small glob onto the neuron of interest, but it is not adhering very well. What can I do?

This paste, which has DiI C 18 uniformly dispersed within a proprietary hydrophobic carrier, is commonly used to dab onto larger areas than smaller areas commonly used with crystals. Any moisture on the area the paste is applied may be the cause for lack of adherence. Apply the paste using a small flat-head spatula or toothpick and keep it in place a bit longer to ensure contact. The area may also be covered with parafilm to ensure contact as well. Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center .

Question 1

I am doing retrograde neuronal labeling using the NeuroTrace DiI Paste.  I apply a small glob onto the neuron of interest, but it is not adhering very well. What can I do?

Accepted Answer

This paste, which has DiI C₁₈ uniformly dispersed within a proprietary hydrophobic carrier, is commonly used to dab onto larger areas than smaller areas commonly used with crystals. Any moisture on the area the paste is applied may be the cause for lack of adherence. Apply the paste using a small flat-head spatula or toothpick and keep it in place a bit longer to ensure contact. The area may also be covered with parafilm to ensure contact as well.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

Question 2

How long does it take for lipophlic tracers to transport along the membrane? How much faster are the FAST lipophilic dyes?

Accepted Answer

The transport is fairly slow, around 6 mm/day in live tissue and slower in fixed tissue, so diffusion of lipophilic carbocyanine tracers from the point of their application to the terminus of a neuron can take several days to weeks The FAST DiO and DiI analogs (which have unsaturated alkyl tails) can improve transport rate by around 50%.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

Question 3

Which form of the lipophilic tracers (DiO, DiI, DiD, etc) should I use?

Accepted Answer

Select the dye that is compatible with your available excitation source(s) and emission filter set/channels. The solid, paste and crystal forms can be applied directly to neurons in tissues. For labeling cells in culture or microinjection, the lipophilic dyes in solution or solid form can be used.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

Question 4

How do I know which tracer to choose for my experiment?

Accepted Answer

Factors to consider are size of tracer, method of delivery (injection, direct application to tissue, etc.), and if the tracer needs to be fixable. Here are some links to details about the various classes of neuronal tracers we offer and how to choose between them:

Neuronal Tracing (https://www.thermofisher.com/us/en/home/life-science/cell-analysis/cell-tracing-tracking-and-morphology/neuronal-tracing.html)
Choosing a Tracer (https://www.thermofisher.com/us/en/home/references/molecular-probes-the-handbook/fluorescent-tracers-of-cell-morphology-and-fluid-flow/choosing-a-tracer.html)
Imaging Analysis (http://assets.thermofisher.com/TFS-Assets/BID/Reference-Materials/bioprobes-50-journal.pdf)

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

Question 5

What products do you have for neuronal tracing?

Accepted Answer

Please check out this web page (https://www.thermofisher.com/us/en/home/life-science/cell-analysis/cell-tracing-tracking-and-morphology/neuronal-tracing.html) for details.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

NeuroTrace™ DiI Tissue-Labeling Paste - FAQs

I am doing retrograde neuronal labeling using the NeuroTrace DiI Paste. I apply a small glob onto the neuron of interest, but it is not adhering very well. What can I do?

How long does it take for lipophlic tracers to transport along the membrane? How much faster are the FAST lipophilic dyes?

Which form of the lipophilic tracers (DiO, DiI, DiD, etc) should I use?

How do I know which tracer to choose for my experiment?

What products do you have for neuronal tracing?