These low molecular weight polar tracers cross gap junctions and follow neuronal projections. Offered in a range of fluorescent colors, they can be multiplexed with other probes, and biocytins easily accept secondary detection for effective signal amplification.
With low molecular weights (<1,000 Da) and bright fluorescent signals, these cell-impermeant polar tracers can be employed to trace neuronal projections and investigate gap junctions. They are fixable and photostable and are offered in multiple colors for multiplexing with other fluorescent probes. Biocytins can also be detected using fluorescent streptavidin conjugates for signal amplification. Because they cross gap junctions, biocytins and hydrazides are often used to investigate neuronal communication in conjunction with labeled dextrans, which are retained within the cell. |
![]() Confocal image stack of a 10,000 MW Calcium Green dextran–labeled climbing fiber in a sagittal cerebellar slice, showing incoming axon and terminal arborization (in yellow). The Purkinje cell innervated by this fiber was labeled with Alexa Fluor® 568 hydrazide. |
Properties
Readout | Direct fluorescence imaging of cells |
Tissue sections | Yes |
In vivo neurons | Yes |
Fixed tissue sections | No |
Cultured cells | Yes |
Cell loading | Microinjection, iontophoresis |
Staining mode | Endogenous |
Best for | Single cells |
Fixable | ![]() |
Transport | Bidirectional |
Photobleaching resistance | ![]() |
Synaptic transfer | No |
Gap junction transfer | Yes |
Bibliography | Citations |
Selection Guide
Carrier
|
Standard filter set(s)
|
Fluorophore
|
Ex/Em (nm)
|
Quantity
|
Cat. No.
|
|
---|---|---|---|---|---|---|
Alexa Fluor® 350 Hydrazide | Hydrazide, sodium salt | DAPI | Alexa Fluor® 350 | 346/442 | 5 mg | A10439 |
Alexa Fluor® 488 Hydrazide | FITC | Alexa Fluor® 488 | 495/519 | 5 mg | A10436 | |
Alexa Fluor® 568 Hydrazide | Rhodamine | Alexa Fluor® 568 | 578/603 | 5 mg | A10437 | |
Alexa Fluor® 594 Hydrazide | Texas Red® | Alexa Fluor® 594 | 590/617 | 5 mg | A10438 | |
Alexa Fluor® 555 Hydrazide | Hydrazide, Tris(triethylammonium) salt |
TRITC | Alexa Fluor® 555 | 555/565 | 1 mg | A20501MP |
Alexa Fluor® 633 Hydrazide | Texas Red® | Alexa Fluor® 633 | 632/647 | 1 mg | A30634 | |
Alexa Fluor® 647 Hydrazide | Cy®5 | Alexa Fluor® 647 | 650/668 | 1 mg | A20502 |
Properties
Readout |
Direct fluorescence imaging of cells; biocytins easily accept secondary detection to amplify weak signals
|
---|---|
Tissue sections | Yes |
In vivo neurons | Yes |
Fixed tissue sections | No |
Cultured cells | Yes |
Cell loading | Microinjection, iontophoresis |
Staining mode | Endogenous |
Best for | Single cells |
Fixable | ![]() |
Transport | Bidirectional |
Photobleaching resistance | ![]() |
Synaptic transfer | No |
Gap junction transfer | Yes |
Bibliography | Citations |
Selection Guide
Carrier |
Standard filter set(s)
|
Fluorophore
|
Ex/Em (nm)
|
Quantity
|
Cat. No.
|
|
---|---|---|---|---|---|---|
Alexa Fluor® 488 Biocytin |
Biocytin, |
FITC | Alexa Fluor® 488 | 495/519 | 250 μg | A12924 |
Alexa Fluor® 546 Biocytin | TRITC | Alexa Fluor® 546 | 556/573 | 250 μg | A12923 | |
Alexa Fluor® 594 Biocytin | Texas Red® | Alexa Fluor® 594 | 590/617 | 250 μg | A12922 |
Properties
Readout | Direct fluorescence imaging of cells |
Tissue sections | Yes |
In vivo neurons | Yes |
Fixed tissue sections | No |
Cultured cells | Yes |
Cell loading | Microinjection, iontophoresis |
Staining mode | Endogenous |
Best for | Single cells |
Fixable | ![]() |
Transport | Bidirectional |
Photobleaching resistance | ![]() |
Synaptic transfer | No |
Gap junction transfer | Yes |
Bibliography | Citations |
Selection Guide
Carrier
|
Standard filter set(s)
|
Fluorophore
|
Ex/Em (nm)
|
Quantity
|
Cat. No.
|
|
---|---|---|---|---|---|---|
Alexa Fluor® 350 Hydrazide | Hydrazide, sodium salt | DAPI | Alexa Fluor® 350 | 346/442 | 5 mg | A10439 |
Alexa Fluor® 488 Hydrazide | FITC | Alexa Fluor® 488 | 495/519 | 5 mg | A10436 | |
Alexa Fluor® 568 Hydrazide | Rhodamine | Alexa Fluor® 568 | 578/603 | 5 mg | A10437 | |
Alexa Fluor® 594 Hydrazide | Texas Red® | Alexa Fluor® 594 | 590/617 | 5 mg | A10438 | |
Alexa Fluor® 555 Hydrazide | Hydrazide, Tris(triethylammonium) salt |
TRITC | Alexa Fluor® 555 | 555/565 | 1 mg | A20501MP |
Alexa Fluor® 633 Hydrazide | Texas Red® | Alexa Fluor® 633 | 632/647 | 1 mg | A30634 | |
Alexa Fluor® 647 Hydrazide | Cy®5 | Alexa Fluor® 647 | 650/668 | 1 mg | A20502 |
Properties
Readout |
Direct fluorescence imaging of cells; biocytins easily accept secondary detection to amplify weak signals
|
---|---|
Tissue sections | Yes |
In vivo neurons | Yes |
Fixed tissue sections | No |
Cultured cells | Yes |
Cell loading | Microinjection, iontophoresis |
Staining mode | Endogenous |
Best for | Single cells |
Fixable | ![]() |
Transport | Bidirectional |
Photobleaching resistance | ![]() |
Synaptic transfer | No |
Gap junction transfer | Yes |
Bibliography | Citations |
Selection Guide
Carrier |
Standard filter set(s)
|
Fluorophore
|
Ex/Em (nm)
|
Quantity
|
Cat. No.
|
|
---|---|---|---|---|---|---|
Alexa Fluor® 488 Biocytin |
Biocytin, |
FITC | Alexa Fluor® 488 | 495/519 | 250 μg | A12924 |
Alexa Fluor® 546 Biocytin | TRITC | Alexa Fluor® 546 | 556/573 | 250 μg | A12923 | |
Alexa Fluor® 594 Biocytin | Texas Red® | Alexa Fluor® 594 | 590/617 | 250 μg | A12922 |