Solutions and Reagents

Preparation of Standards a. Stock standard. i. Cyromazine stock 1 mg/mL. Prepare by dissolving 10 mg of the compound in 10 mL of 50% acetone/methanol, v/v. ii. Melamine stock 0.05 mg/mL. Prepare by dissolving 10 mg of the compound in 200 mL of 50% acetone/methanol, v/v. b. Working standard 1 / g/mL. i. Cyromazine standard Dilute 10 / L of the stock standard (a.i) into 10 mL volumetric flask and bring up to volume with acetone. ii. Melamine standard Dilute 200 pL of the stock standard (a.ii) into 10 mL volumetric flask and bring up to volume with acetone. 

Storage Conditions Refer to Determinative Method, section D.3. 

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Reagents and solutions. APDC solution. Dissolve 1.0 g of APDC in water, dilute to 100 mL and filter (Note 1). 

Subpart E - Testing Facilities Operation Sec. 58.81 Standard operating procedures. Sec. 58.83 Reagents and solutions. 

Reagents and solutions must be clearly identified, including shelf-lives and storage conditions if required. There must be adequate supplies for the length of the study. 

The reagents and solutions used must be kept anhydrous and necessary care should be taken throughout to prevent exposure to atmospheric moisture,... 

Chemicals, Reagents, and Solutions should be labelled to indicate identity (with concentration, if appropriate),... 

Chemicals, reagent and solutions should be labeled to indicate identity, expiry and specific storage instructions. 

SOPs can be both general and specific. Examples of general laboratory operations include how to characterize an analytical standard, how to record observations and data, and how to label reagents and solutions. Most laboratory operations even have an SOP for writing and updating SOPs. Examples of specific laboratory operations include the preparation and analysis of a specific company s product or raw material, the operation and calibration of specific instruments, and the preparation of specific samples for analysis. Often, SOPs are based on published methods, such as those found in scientific journals, in application notes, and procedures published by instrument manufacturers, or in books of standard methods, such as those published by the American Society for Testing and Materials (ASTM) and the Association of Official Analytical Chemists (AOAC). The published... 

All reagents and solutions in the laboratory areas shall be labeled to indicate identity, titer or concentration, storage requirements, and expiration date."... 

The best guarantee that outdated reagents and solutions win not be used is a strictly enforced pohcy for discard of such materials, although that is not a GLP requirement. The GLPs require only that outdated materials not be used. 

Performing the assay is reduced to putting an alcoholic solution of the analysed sample, Folin-Ciocalteu reagent and solution of sodium carbonate into a reaction tube, which brings the pH of the reaction environment to approx. 10. According to various literature reports, the reaction runs in the darkness for 10 to 120 minutes. After that time, the blue colour of the solution is observed colorimetrically at 725 nm - 760 nm [34, 35, 36, 37, 38]. The results are expressed based on calibration curves prepared for catechol and gallic acid. 

It is recommended that precast gels be obtained commercially (Jule or Novex). They are cost- and time-effective and they come in a variety of sizes and types. If students are to make their own gels, the following items, reagents, and solutions should be provided. Many types of gel casters are commercially available. 

To prepare a 12% acrylamide gel, mix the following reagents and solutions in a 50-mL Erlenmeyer flask ... 

Materials and Supplies. A complete list of all materials, supplies, and equipment required for the experiment is provided. An Instructor s Manual describing the preparation of all reagents and solutions and advice on how to set up a biochemistry laboratory is available from the publisher. 

Fluorescence emission is a linear function of concentration only over a limited range. REAGENTS AND SOLUTIONS... 

The mass of enzyme (ME) is based on a recommended enzyme/substrate ratio of 2%. The four-enzyme cocktail (see Reagents and Solutions) has 2.8 mg protein/ml, so a volume of 0.71 ml is needed. At 7 U/ml, this gives 5 U enzyme in the reaction. 

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