We’re highlighting one of our antibodies, a rabbit polyclonal against Melanopsin. This antibody is offered as both serum (AB-N38) and affinity purified (AB-N39). Intrinsically photosensitive retinal ganglion cells (ipRGCs) are cells that express melanopsin. These ipRGCs, with their long processes, are involved in the perception of light and dark and are circadian rhythm determinants. Our Melanopsin antibody recognizes a portion of the N-terminal region of the mouse melanopsin extracellular domain and does not cross-react with melanopsins of other species, so it’s specific to mouse.
Here is how other researchers are using them in recent publications. This Melanopsin antibody may be the antibody your lab needs.
Kim et. al. used (AB-N38) at a 1:2,000 dilution to quantify ipRGCs in the retina and confirm that Per1-deficiency did not affect melanopsin-positive cell abundance.
And finally, Zhu et. al. using affinity purified (AB-N39) at a 1:2000 dilution to identify and quantify ipRGCs in retinal whole-mounts following ischemic injury.
Kim P, Kumar V, Garner N, Jayasingh O, Roman G, Walters S, Vo T, Nguyen Q, Bowles J, Woodruff T, Inder W, Hunt J, Heyde I, Oster H, Rawashdeh O (2025) A systemic clock brake: Period1 stabilizes the circadian network under environmental stress. bioRxiv 2025.06.12.659230. doi: 10.1101/2025.06.12.659230
Objective: To investigate the role of the core circadian clock gene Period1 (Per1) in regulating light-induced circadian realignment and systemic physiological stability across central and peripheral tissues.
Summary: Per1-deficient mice showed accelerated behavioral, hormonal, and metabolic re-entrainment to shifted light-dark cycles, highlighting Per1’s role as a buffer that stabilizes circadian responses. Despite faster adaptation, Per1 deletion compromised SCN network coherence and increased peripheral metabolic phase instability.
Usage: Melanopsin (OPN4) was detected using Anti-Melanopsin (AB-N38) at a 1:2000 dilution to quantify ipRGCs in the retina and confirm that Per1-deficiency did not affect melanopsin-positive cell abundance.
Zhu M, Wu Y, Gao H, Qi F, Zhang X, Ran Y (2025) Differential regulation of mTOR activity in retinal ganglion cells underlies their distinct susceptibility to ischemia/reperfusion. Commun Biol 8(1):911. doi: 10.1038/s42003-025-08314-2 PMID: 40500296
Objective: To explore why intrinsically photosensitive retinal ganglion cells (ipRGCs) are more resistant to ischemia/reperfusion (I/R) injury than other RGC subtypes and to examine the role of mTOR signaling in this differential vulnerability.
Summary: ipRGCs exhibited higher mTOR activity and greater resistance to I/R injury compared to other RGCs. Rapamycin had cell-type–specific effects: it protected non-ipRGCs by increasing mTOR activity but suppressed mTOR in ipRGCs unless light was removed, revealing that light conditions critically influence mTOR-mediated neuroprotection.
Usage: Melanopsin (OPN4) was detected using Anti-Melanopsin (AB-N39) at a 1:2000 dilution to identify and quantify ipRGCs in retinal whole-mounts following ischemic injury.
Son S, Beaudoin DL, Hassan AR, Akpo MS, Ichinose T, Garrett AM (2025) A characterization of mouse retinal ganglion cell types labeled with AAV tools. bioRxiv 2025.06.02.657062. doi: 10.1101/2025.06.02.657062
Objective: To characterize the cell-type specificity and functional diversity of retinal ganglion cells (RGCs) labeled by AAV vectors carrying synthetic promoters ProA13 and ProA27 in the mouse retina.
Summary: ProA13 and ProA27 AAV vectors selectively labeled molecularly and morphologically distinct subsets of RGCs, including melanopsin-positive ipRGC subtypes. ProA27 labeled a broader diversity of ipRGCs (M1–M4), while ProA13 primarily labeled M1 cells, enabling analysis of their structural, functional, and projection differences.
Usage: Melanopsin (OPN4) was detected using Anti-Melanopsin (AB-N38) at a 1:5000 dilution to identify and classify ipRGCs in AAV-labeled retinas.
McLeod CM, Son S, Haque MN, Garrett AM (2025) Reduced neuronal self-avoidance in mouse starburst amacrine cells with only one Pcdhg isoform. bioRxiv 2025.05.29.656828. doi: 10.1101/2025.05.29.656828
Objective: To determine whether the γC4 isoform of the protocadherin-γ (Pcdhg) gene cluster is sufficient to mediate neuronal self-avoidance in starburst amacrine cells (SACs) in the mouse retina.
Summary: While deletion of γC4 or γC5 alone did not impair SAC self-avoidance, mice expressing only γC4 exhibited significant failures in dendritic self-avoidance that were not fully rescued by transgenic overexpression. These findings suggest γC4 is specialized for neuronal survival but insufficient to support self-avoidance on its own.
Usage: Melanopsin (OPN4) was detected using Anti-Melanopsin (AB-N38) at a 1:2000 dilution to label intrinsically photosensitive retinal ganglion cells (ipRGCs) for analysis of retinal cell spacing and mosaic organization.
Semo M, Hughes S, Smyllie NJ, Patton AP, Pothecary CA, Tam SKE, Buckland J, Brown LA (2025) Magnetic fields influence visual responses in mice. bioRxiv 2025.05.12.653455. doi: 10.1101/2025.05.12.653455
Objective: To investigate whether magnetic fields influence mammalian retinal function and to determine the role of cryptochromes in mediating this effect.
Summary: This study demonstrates that magnetic fields modulate neuronal activity in the mouse retina in a light-dependent and cryptochrome-dependent manner. Magnetic fields altered c-Fos expression in melanopsin-positive retinal ganglion cells and influenced retinal circadian rhythms and behavior.
Usage: Melanopsin (OPN4) expression was assessed using Anti-Melanopsin (AB-N38) at a 1:2500 dilution to label ipRGCs during immunohistochemical analysis of retinal responses to light and magnetic fields.
Kiyama T, Chen CK, Altay HY, Chen YJ, Sigala L, Su D, Eliason S, Amendt BA, Mao CA (2025) Tbr2-dependent parallel pathways regulate the development of distinct ipRGC subtypes. bioRxiv 2025.04.29.651262. doi: 10.1101/2025.04.29.651262
Objective: To demonstrate that two Tbr2-dependent transcription factors, Iroquois‑related homeobox 1 (Irx1) and T-box containing factor 20 (Tbx20), are key downstream transcription factors guiding lineage segregations of Tbr2-expressing RGC into distinct adult intrinsically photo sensitive retinal ganglion cells (ipRGC) subtypes.
Summary: Both transcription factors, Irx1 and Tbx20, also control Opn4 expression. When Irx1 is ablated during retinal development, Opn4 expression is significantly reduced in the M3, M4, and M5 ipRGC groups; however, the formation of Irx1-expressing ipRGCs is not affected. In contrast, when Tbx20 is deleted, a significant number of Tbx20-expressing cells fail to develop while Opn4 expression is down-regulated. These findings reveal two parallel transcription cascades downstream of Tbr2 for controlling ipRGC subtype formation, fate divergence, and maintenance in the adult retina.
Usage: Retinal sections or flat-mounted retinas were fixed with 4% paraformaldehyde and then incubated with the Anti-Melanopsin (AB-N39).
Bohl JM, Hassan AR, Sharpe ZJ, Kola M, Shehu A, Beaudoin DL, Ichinose T (2025) Pivotal roles of melanopsin containing retinal ganglion cells in pupillary light reflex in photopic conditions. 19:1547066. doi: 10.3389/fncel.2025.1547066 PMID: 39990971
Objective: To examine the roles of intrinsically photosensitive retinal ganglion cells (ipRGCs) in the pupillary light reflex (PLR) by ablating photoreceptors using N-nitroso-N-methylurea (MNU).
Summary: Results suggest that ipRGCs primarily contribute to the PLR at a high light intensity, which does not agree with the previous results shown by mutant mouse models. The results indicate that the melanopsin response in ipRGCs generate fast and robust PLR when induced by high light.
Usage: Retinal whole mount preparations were fixed using 4% paraformaldehyde and blocked with 10% normal donkey serum and 0.5% Triton-X in PBS (PBS-T). Melanopsin antibody (AB-N39) was used at 1:5000 in PBS-T and was incubated for 3 days at 4°C, followed by Alexa568 donkey-anti-rabbit for 2 h.
Zhang Q, Xue J, Tang J, Wu S, Liu Z, Wu C, Liu C, Liu Y, Lin J, Han J, Liu L, Chen Y, Yang J, Li Z, Zhao L, Wei Y, Li Y, Zhuo Y (2024) Modulating amacrine cell-derived dopamine signaling promotes optic nerve regeneration and preserves visual function. Sci Adv 10(31):eado0866. doi: 10.1126/sciadv.ado0866 PMID: 39093964
Objective: To identify a unique subtype of amacrine cells (ACs), dopaminergic ACs (DACs), that respond early to optic nerve crush by downregulating neuronal activity and reducing retinal dopamine (DA) release.
Summary: Activation of DACs or augmentation of DA release using levodopa demonstrated neuroprotective effects and modestly enhanced axon regeneration. The dopamine receptor D1 (DRD1) was also identified as a critical mediator of DAC-derived DA, and retinal ganglion cell (RGC)-specific DRD1 overexpression effectively overcame subtype-specific barriers to regeneration.
Usage: Immunostaining of retinal cryosections and whole mounts (1:1000) (AB-N39).
Kiyokawa Y, Ootaki M, Kambe Y, Tanaka KD, Kimura G, Tanikawa T, Takeuchi Y (2024) Approach/avoidance behavior to novel objects is correlated with the serotonergic and dopaminergic systems in the brown rat (rattus norvegicus). Neuroscience 549:110-120. doi: 10.1016/j.neuroscience.2024.05.003 PMID: 38723837
Objective: To compare the dopaminergic, serotonergic, and noradrenergic systems immunohistochemically among rats.
Summary: The serotonergic system suppresses avoidance behavior, while the dopaminergic system enhances approach behavior to novel objects.
