029010 Gram Stain

Introduction

Intended Use

For the enumeration of enterococci in water and other liquids by the membrane filtration technique.

Principle and Interpretation

The growth of the entire accompanying Gram-negative microbial flora is inhibited by sodium azide. Enterococci reduce 2,3,5-Triphenyl tetrazolium chloride (TTC) to give a red formazan inside the bacterial cell, their colonies are thus red. Nitrogen, minerals, and amino acids are provided by the tryptose whilst yeast extract supplies vitamins. Glucose acts as the carbon source, dipotassium phosphate buffers the medium, and agar-agar is the solidifying agent.

Formulation

Ingredients	/liter
Tryptose	20.0g
Yeast extract	5.0g
Glucose	2.0g
Disodium hydrogen phosphate	4.0g
Sodium azide	0.4g
2,3,5-Triphenyl Tetrazolium chloride	0.1g
Agar	10.0g
pH 7.2±0.1 at 25°C

Preparation

Dissolve 41.5 g in 1 L of purified water. Heat in boiling water and agitate frequently until completely dissolved. Sterilize by further heat for 20 minutes in the boiling water bath.

Quality Control

Cultural characteristics observed after incubation at 34-38°C for 40-48hours

Quality control strains	Growth	Colony color
Enterococcus faecalis ATCC29212	Good growth,PR≥0.5	deep red coloured colonies
Escherichia coli ATCC25922	Total inhibition	–

Sorage and Shelf Life

Keep container tightly closed, store in a cool, dry place, away from bright light. Storage period of 3 years.

Precautions

1. When weighing the dehydrated medium, please wear masks to avoid causing respiratory system discomfort

2. Keep container tightly closed after using to prevent clumping.

Waste Disposal

Microbiological contamination was disposed by autoclaving at 121°C for 30 minutes.

Intended Use For the enumeration of enterococci in water and other liquids by the membrane filtration technique. Principle and Interpretation The growth of the entire accompanying Gram-neg……

Description

For rapid, sensitive and accurate screening of potential Tyrosinase inhibitors

---

Tyrosinase (EC 1.14.18.1) is a copper-binding enzyme that is expressed across a vast range of species ranging from bacteria and fungi to mammals. It is involved in two sequential reactions of the melanin synthesis pathway: first being the hydroxylation of a monophenol and second the conversion of an ortho-diphenol to a quinone. Quinone then undergoes a series of reactions including polymerization to form melanin.

Tyrosinase is of great interest to the agriculture industry since it causes browning of fruits, vegetable, and mushrooms, as well as to the cosmetic industry as it causes skin darkening. Development and screening of tyrosinase inhibitors, therefore, is very useful for conditions such as hyperpigmentation and melasma. Tyrosinase activity is significantly increased in melanoma. Therefore, the detection of tyrosinase activity could be promising as a specific diagnostic test for melanoma and may be useful in monitoring patient response to melanoma treatments.

This Tyrosinase Activity Assay Kit is a simple one-step, plate-based assay for the measurement of tyrosinase activity in biological samples. In this assay, tyrosinase catalyzes the conversion of a phenolic substrate to a Quinone intermediate, which reacts with the tyrosine enhancer forming a highly stable chromophore with absorbance at 520 nm. The assay can detect as low as 30 μU Tyrosinase in biological samples.

Highly reproducibility
Highly Sensitive Assay to Screen for Tyrosinase Activity
Stable formulation of ready to use Reaction Facilitator (tyrosinase)

Bis-propargyl-PEG10 is reactive with azide-bearing compounds or biomolecules in copper catalyzed Click Chemistry. By introducing PEG units into the molecule, the solubility of the compound in aqueous environment can be improved. Reagent grade, for research purpose. Please contact us for GMP-grade inquiries.

Bis-propargyl-PEG10 is reactive with azide-bearing compounds or biomolecules in copper catalyzed Click Chemistry. By introducing PEG units into the molecule, the solubility of the compound in aqueous environment can be improved. Reagent grade, for research purpose. Please contact us for GMP-grade inquiries.