About CD40
This gene is a member of the TNF-receptor superfamily. The encoded protein is a receptor on antigen-presenting cells of the immune system and is essential for mediating a broad variety of immune and inflammatory responses including T cell-dependent immunoglobulin class switching, memory B cell development, and germinal center formation. AT-hook transcription factor AKNA is reported to coordinately regulate the expression of this receptor and its ligand, which may be important for homotypic cell interactions. Adaptor protein TNFR2 interacts with this receptor and serves as a mediator of the signal transduction. The interaction of this receptor and its ligand is found to be necessary for amyloid-beta-induced microglial activation, and thus is thought to be an early event in Alzheimer disease pathogenesis. Mutations affecting this gene are the cause of autosomal recessive hyper-IgM immunodeficiency type 3 (HIGM3). Multiple alternatively spliced transcript variants of this gene encoding distinct isoforms have been reported. [provided by RefSeq, Nov 2014]

About Brilliant Violet 421
Brilliant™ Violet 421 (BV421) is a Violet-emitting non-tandem polymer fluorophore that can be excited by the 405 nm Violet laser and collected using a 450/50 bandpass filter. BV421 has an excitation peak at 405 nm and an emission peak at 421 nm, and is spectrally similar to Alexa Fluor™ 405 and Cascade Blue. Other dyes that are considered similar include SuperNova V428 (Beckman Coulter), StarBright Violet 440 (Bio-Rad) and SuperBright 436 (Thermo Fisher). BV421 is very bright and is most commonly used for flow cytometry. Its photostablity, fixation stablity, and non-toxicity properties also make BV421 useful for cell sorting and live cell Fluorescence Microscopy applications. This dye is part of the Brilliant™ Violet dye line of fluorescent polymers. Brilliant™ Violet 421 polymer is employed as the donor molecule in a series of tandem dyes with acceptor molecules emitting at various points across the visible light spectrum. The Brilliant™ Violet dyes are a superior alternative to QDot nanocrystals and similar to SuperNova dye from Beckman Coulter and StarBright dyes from Bio-Rad.