L_Products

L-Lactic acid is the optically active form of lactic acid and has an (S) stereochemical arrangement. Animals produce L-Lactate, conjugate base of lactic acid, from pyruvate via lactate dehydrogenase in fermentation during normal metabolism and exercise. Lactic acid bacteria perform lactic acid fermentation, converting carbohydrates to lactic acid. In humans, lactic acid and its conjugate base are part of many biological processes from prenatal development to extracellular fluid surrounding neurons.

Lactic acid is used in food preparation to produce specific types of beer and other alcoholic beverages. When used in the colon it prevents gastrointestinal fermentation, and in an 8% cream has been used on photodamaged skin. Polylactic acid can be formed when two molecules of lactic acid are dehydrated and then catalyzed into a plastic that is both biodegradable and not derived from petrochemicals. It is also used by detergent manufacturers due to its anti-bacterial properties, and can be used to produce water-soluble lactates from otherwise insoluble active ingredients.

L-Leucine 7-amido-4- methylcoumarin hydrochloride is used in leucine aminopeptidase assays as a fluorgenic substrate, showing greater sensitivity when compared to 4-methoxynapthylamide assays. Aside from the leucine aminopeptidase enzyme, L-Leucine 7-amido-4- methylcoumarin hydrochloride also works as a fluorogenic subtsrate for broad specificity aminopeptidases, such as aminopeptidase M.

The result of enzymatic activity yields a bright blue fluorescent dye: 7-amino-4methylcoumarin (excitation 380nm emission 440nm).

Leucine aminopeptidase enzymes are found across a wide range of organisms including bacteria, plants and animals, and it has been detected in human tissues, with high activity observed in the kidney and liver.

L-Leucine beta-naphthylamide hydrochloride is a substrate for leucine aminopeptidase and similar aminopeptidases like aminopeptidase M. It is analyzed by fluorescence analysis or coupled with a coupling reagent like p-dimethylaminocinnamaldehyde to form a colored precipitate.

Tested and Certified for in vivo imaging (See "Luciferin FAQ" in additional information)

Luciferin is a common bioluminescent reporter used for in vivo imaging of the expression of luciferase. This water soluble substrate for the firefly luciferase enzyme utilizes ATP and Mg2+ as cofactors to emit a characteristic yellow-green emission in the presence of oxygen, which shifts to red light in vivo at 37°C. Through the utilization of ATP, the reaction can be further used to indicate the presence of energy or life in order to function as a life-death stain.

Luciferin is a common reagent used throughout the biotechnology field and specifically for in vivo imaging. Luciferase labeled tumor cells, stem cells or infectious diseases are often inoculated into research animals such as rats or mice for investigation. The injection of Luciferin allows for the real-time, noninvasive monitoring of disease progression and/or drug efficacy in these model systems through Bioluminescence Imaging (BLI).

Luciferin is also commonly used for in vitro research, including luciferase and ATP assays, gene reporter assays, high throughput sequencing and various contamination assays.

L-Luciferin is the chiralic sister to D-luciferin. While most researchers claim that L-luciferin does not produce any light, Lembert has reported that it produces a very weak and extremely slow manifesting light (Lembert, 1996). Nakamura suggested that an enzyme system incorporating luciferase might be responsible for changing the chirality of the L-luciferin to D-luciferin (Nakamura et al., 2006) (See Reference Library).

L-Lysyl-L-alanine 7-amido-4-methylcoumarin is used as an AMC fluorogenic substrate.

Methionine functions as a reagent and with metals in non-biological applications, L-methionine in particular has been used with metals to form photosensitizers and ligands for transition metal catalyzed bond forming reactions. [11C]L-Methionine has also been used in Positron Emission Tomography of brain tumors for diagnostic purposes.

Methionine is an alpha amino acid used in protein synthesis. In human beings methionine is a vital amino acid not synthesized in the human body and must therefore be ingested. Methionine in the human body is used to improve skin elasticity and tone, tissue growth and repair, and keratin systems such as hair and nails. As a detoxifying agent methionine chelates heavy metals, while the sulfur in it protects cells. L-Methionine is an enantiomerically active amino acid used in the body.

L-Threonine 7-amido-4-methylcoumarin is an AMC fluorgenic substrate.

L-Tyrosine 7-amido-4-methylcoumarin is used as an AMC fluorogenic substrate.

Lactitol is a disaccharide binding a beta-D-galactopyranose and D-glucitol to produce the sugar alcohol also known as Lactitol. It’s derived from lactose, a product of disaccharide’s glucose being reduced. It has been used as a laxative agent, excipient, and low-calorie artificial sweetener. Other characteristics of Lactitol display antibiotic and prebiotic activity.

Studies have demonstrated Lactitol decreases cholesterol metabolism and can treat liver diseases like hepatic encephalopathy. This function arises from the management of ammonia in the blood following cirrhotic damage to the liver. Revertant bacteria and aberrant cells were not seen to increase with the administration of Lactitol as a therapeutic substance, suggesting no mutagenicity.

Further properties increased bifidobacteria and lactobacilli after Lactitol consumption. One survey also recorded PYY and GLP-1 levels rising with ingestion of Lactitol. In a study on fecal flora, low dosage of Lactitol did not change pH; it also had no effect on the colonization of necessary anaerobes, aerobes or Enterobacteriaceae. These results promote Lactitol’s probiotic qualities.

Lactobionic acid is a sugar acid formed from gluconic acid and galactose. It possesses antioxidant activity and is used in development of targeting drug delivery systems, such as silica nanoparticles. Lactobionic acid can be used as an iron chelator, making it useful as part of a solution for organ preservation.

GoldBio’s LBA4404 Agrobacterium chemically competent cells allow you to obtain high transformation efficiency in applications such as gDNA or cDNA library construction. Our LBA4404 strain harbors a rifampicin resistance (rif) gene. Furthermore, LBA4404 has an octoprine-type Ti plasmid pAL4404 without self-transport function, containing the vir genes. Our LBA4404 strain can be used in genetic transformation of tomato, tobacco and other plants.

Product Specifications
Competent cell type: Chemical Competent
Species: A. tumefaciens
Strain: LBA4404
Transformation efficiency: ≥1 x 10⁴ cfu/µg pCAMBIA1391z DNA
Blue/white screening: No

GoldBio’s LBA4404 ElectroCompetent Agrobacterium cells allow you to obtain high transformation efficiency in applications such as gDNA or cDNA library construction. Our LBA4404 strain harbor a rifampicin resistance (rif) gene. Furthermore, LBA4404 has an octoprine-type Ti plasmid pAL4404 without self-transport function, containing the vir genes. Our LBA4404 strain can be used in genetic transformation of tomato, tobacco and other plants.

Product Specifications
Competent cell type: ElectroCompetent
Species: A. tumefaciens
Strain: LBA4404
Transformation efficiency: ≥4 x 10⁶ cfu/µg pCAMBIA1391z DNA
Blue/white screening: No

Leupeptin hemisulfate (Ac-Leu-Leu-argininal) is a reversible inhibitor of serine and cysteine endopeptidases. Leupeptin hemisulfate is capable of inhibiting plasmin, trypsin, papain, kallikrein, calpain and cathepsin B. Leupeptin is usually used in a concentration range of 10 to 100μM. Leupeptin is widely used in many protease inhibitor cocktails due to its potency, low toxicity, and range of inhibition. Leupeptin is also used in a quantitative assay to measure macroautophagic flux in mammals and is being investigated for its use in treating malaria.

Levofloxacin is a fluoroquinolone antibiotic that is an optical S-(-) isomer of ofloxacin. In vitro susceptibility tests show a large degree of activity towards gram-positive and gram-negative bacteria with moderate anaerobic activity.

Fluoroquinolones are a group of broad-spectrum antibiotics that inhibit DNA synthesis. These antibiotics prevent unwinding of double-stranded DNA by binding DNA gyrase or DNA topoisomerase. By preventing the formation of single-stranded DNA, fluoroquinolones inhibit bacterial replication.

Antibiotics are often used in clinical in vitro tests known as antimicrobial susceptibility tests or ASTs to determine their efficacy against certain bacterial species. They are tested against gram-negative and gram-positive bacteria using panels, discs, and MIC strips by medical microbiologists. ASTs decrease the risk of using an antibiotic against bacteria exhibiting resistance to it, and the results are used in clinical settings to determine which antibiotic(s) to prescribe for various infections.

Leukemia Inhibitory Factor (LIF) is a lymphoid factor which promotes long-term maintenance of embryonic stem cells by suppressing spontaneous differentiation. LIF binds to the specific LIFR-α, which forms a heterodimer containing a GP130 signal transducing subunit.LIF is normally expressed in the trophectoderm of the developing embryo and has a number of other activities including cholinergic neuron differentiation, control of stem cell pluripotency, bone and fat metabolism, mitogenesis of certain factor dependent cell lines and promotion of megakaryocyte production in vivo. LIF is not required for human embryonic stem cell cultures.

Sterile Filtered White lyophilized powder

Leukemia Inhibitory Factor (LIF) is a lymphoid factor which promotes long-term maintenance of embryonic stem cells by suppressing spontaneous differentiation. LIF binds to the specific LIFR-α, which forms a heterodimer containing a GP130 signal transducing subunit.LIF is normally expressed in the trophectoderm of the developing embryo and has a number of other activities including cholinergic neuron differentiation, control of stem cell pluripotency, bone and fat metabolism, mitogenesis of certain factor dependent cell lines and promotion of megakaryocyte production in vivo. While LIF is not required for human embryonic stem cell cultures, it is commonly used for mouse embryonic stem cell cultures.

Sterile Filtered White lyophilized powder