C-kit ligand, the recently identified ligand for the kit tyrosine kinase receptor, is mapped to the mouse S1 locus. This pleiotropic cytokine, alternately known as stem cell factor (SCF), mast cell growth factor (MGF) and steel-factor (SLF), plays essential roles in gametogenesis, melanogenesis and early stages of hematopoiesis. In vitro and in vivo, KITLG can stimulate the proliferation of mature, as well as the proliferation and maturation of immature, mast cells. KITLG acts in a synergistic manner on purified primitive human and mouse hematopoietic precursors, with various growth factors (such as IL1, IL3, IL6, IL7, and Epo), to induce myeloid, erythroid and lymphoid lineage colony formation. The finding that KITLG is also expressed in the nervous system suggests a possible role for KITLG in the development of the nervous system.

Sterile Filtered White lyophilized powder. Purified and tested for use in cell culture.

KIT Ligand (KITLG), also called Stem Cell Factor (SCF) which binds to the c-Kit receptor is produced by fibroblasts and endothelial cells. The soluble and transmembrane forms of the protein are formed by alternative splicing of the same RNA transcript and the presence of both soluble and transmembrane SCF is required for normal hematopoietic function. SCF plays an important role in hematopoiesis, spermatogenesis and melanogenesis and it promotes mast cell adhesion, migration, proliferation, and survival. Rat KITLG shares 75­-90% amino acid sequence identity with canine, feline, mouse, and human KITLG. Furthermore, rat KITLG is active on mouse and human cells, but human KITLG is only weakly active on mouse cells.

Kojic acid is a chelation agent produced by fungi. It’s used to prevent oxidative browning and to preserve color, along with treating skin diseases like melisma. In its crystal form, along with quercetin, it possesses cytotoxic activity to human cervical cancer cells and colon cancer cells. It seems to also be useful for protective effects from radiation-induced damages on mammalian cells. Kojic acid also inhibits catecholase activity of tyrosinase. When exposed to ferric ions it forms a bright red complex.

Kuromanin chloride is an anthocyanin neuroprotectant and antioxidant. It is found in the fruits of several plants and is shown to protect neurons from oxidative stress. Additionally, kuromanin chloride is an ADP-ribosyl cyclase CD38 inhibitor, ultimately suppressing the metabolism of NAD+ and NADP+.

H-Ala-pNAHCl is a substrate for L-alanine aminopeptidase, which is an enzyme that is localized in bacterial cell walls responsible for the cleavage of L-alanine from various peptides. Significant L-alanine aminopeptidase activity is specific to gram-negative microbes. Therefore, H-Ala-pNAHCl can be used in support of evidence that an organism is gram-positive or gram-negative. It is split by L-alanine aminopeptide into L-alanine and 4-nitroanine. The latter compound causes bacterial suspensions to turn yellow.

H-Ala-AMCTFA (L-Alanine 7-amido-4-methylcoumarin, trifluoroacetate salt) is a fluorogenic substrate for aminopeptidase that yields a blue fluorescent solution. This substrate is useful in differentiating between gram-positive and gram-negative bacteria.

L-Albizziine is a white to slightly off-white crystalline powder that is used as a competitive inhibitor of asparagine synthetase in mammalian cells. It can also be used as an inhibitor of both glutamate synthase in ectomycorrhizal fungal isolates, and glutamine metabolism in microbes.

L-Arabinose is an arabinose isomer widely found in nature, while D-arabinose is less common. L-Arabinose is a constituent of many biopolymers that make up plant cell walls.

This monosaccharide is often used in cell culture media, serving as a bacterial carbon source, and can be used to distinguish between bacteria based on their fermentation abilities.

L-Arabinose, in the absence of glucose, induces transcription of the ara operon in E. coli that encodes L-arabinose catabolizing enzymes. It does this by binding to the AraC protein and activating the PBAD promoter. The PBAD promoter is used in plasmid vectors as a switch for protein expression that can be turned on by L-arabinose or turned off by addition of glucose.

L-Arabitol is the reduced alcohol form of L-arabinose. It is produced by some fungus from enzymatic reduction of L-arabinose. L-Arabitol is metabolized by a variety of different bacteria and fungus utilizing an arabitol dehydrogenase enzyme. Arabitol dehydrogenase genes have been introduced into plants to serve as a positive selection marker for transgenic cells. L-Arabitol has been shown to be an inducer of a hydrolytic xylanase enzyme used for catabolism of L-xylose in the saprophytic fungus Hypocrea jecorina.

Arginine is an essential amino acid found in food and plant sources, and many biological systems and is one of only 3 amino acids with basic side chains. Arginine is typically classified as a semi-essential or conditionally essential amino acid. Administered intravenously, Arginine has been shown to stimulate the secretion of human growth hormone and is frequently used in growth hormone stimulation tests. L-Arginine is a substrate of nitric oxide synthase, which is converted to citrulline and nitric oxide and is known to Induces insulin release by a nitric oxide-dependent mechanism.