Page 224 - Demo

Safety Reference
Recipes for Biological, Histological, and Chemical Solutions, continued
1-800-452-1261
flinnsci.com
222
Schiff’s Reagent
Dissolve 0.5 g of fuchsin in 500 mL of DI water. Decolorize solution by passing sulfur dioxide gas through the solution, or add 9 g of sodium bisulfite and 20 mL of 2 M hydrochloric acid to the fuchsin solu- tion. (test for aldehydes)
Schweitzer’s Reagent
Boil a solution of 5 g of copper (II) sulfate pentahydrate in 100 mL of DI water and slowly add 2 M sodium hydroxide solution until precipitation is complete. Filter the copper oxide precipitate, wash with water then dissolve in the minimum volume of 4 M ammonium hydroxide. Also called ammoniacal copper oxide solution. (reagent for dissolving cellulose)
Sebacoyl Chloride/Hexane Solution
Mix 4 mL of sebacoyl chloride with 96 mL of hexanes. (nylon demonstration)
Starch Solution
1% aqueous: Make a smooth paste with 10 g of soluble starch and DI water. Pour the starch paste into 1 L of boiling water while stirring. Cool to room temperature before use. Poor shelf life, always prepare fresh solution. An easier way to make a starch solution is to generously spray ordinary spray starch (the type used for ironing) into DI water. Make fresh. (indicator for iodine)
Sudan III
Warm 73.5 mL of 95% ethyl alcohol in a warm water bath. Add 0.5 g of sudan III and stir. Add 75 °C DI water to just below the 100 mL mark. Stir and cool to room temperature then dilute to 100 mL with DI water. Filter if necessary. (biological stain for fats and lipids)
Sudan IV
Warm 75 mL of 95% ethyl alcohol in a warm water bath. Add 0.5 g sudan IV and stir. Cool to room temperature then dilute to 100 mL with DI water. Filter if neces- sary. (biological stain for fats and lipids)
10X TBE Electrophoresis Buffer
Dissolve 108 g of Tris base [tris(hydroxymethyl)aminomethane], 55 g of boric acid, and 7.5 g of EDTA, disodium salt in 800 mL of DI water, then dilute to 1 L. There is no need to sterilize the solution. If white clumps begin to precipitate in the solution, place the bottle in hot water until the clumps dissolve. Stored at room temper- ature. To use as a buffer, dilute 100-mL of 10X stock to 1 L with DI water.
10X TAE Electrophoresis Buffer
Dissolve 48.4 g of Tris base [tris(hydroxymethyl)aminomethane], 11.4 mL of glacial acetic acid (17.4 M), and 3.7 g of EDTA, disodium salt in 800 mL of DI
water, then dilute to 1 L. There is no need to sterilize the solution. Stored at room temper- ature. To use as a buffer, dilute 100-mL of 10X stock to 1 L with DI water.
Thymol Blue
0.04% aqueous: Mix together 0.04 g of thymol blue and 50 mL of DI water. Add 5 mL of 0.01 M sodium hydroxide solution; stir until all the solid has dissolved. Dilute to 100 mL with DI water. (pH indicator)
Thymol Blue
0.04% aqueous: Dissolve 0.04 g of thymol blue, sodium salt in 75 mL of DI water, then dilute to 100 mL. (pH indicator)
Thymolphthalein
0.04% alcoholic: Dissolve 0.04 g of thy- molphthalein in 75 mL of anhydrous ethyl alcohol, then dilute to 100 mL with anhy- drous ethyl alcohol. (pH indicator)
Tollen’s Reagent
Add 2–3 drops of 2 M sodium hydroxide solution to 5 mL of 0.2 M silver nitrate solution; add 2 M ammonium hydrox- ide solution dropwise until precipitate dissolves. Prepare and use this solution immediately; explosive fulminating silver will form if solution is allowed to stand for any period of time. (test for aldehydes and reducing sugars)
Toluidine Blue O
Mix 1 g of toluidine blue O and 0.5 mL of conc. hydrochloric acid into a homoge- neous paste. While stirring, gradually add
Note: DI water denotes either distilled or deionized water.
the paste to 50 mL of DI water, then dilute to 100 mL of DI water. (biological stain for bacteria)
Universal Indicator
Add 0.18 grams of methyl red and 0.36 grams of phenolphthalein to 550 mL of 95% ethyl alcohol (C2H5OH); stir to dissolve. In a separate container, add 0.43 grams of bromthymol blue to 200 mL of distilled water; stir to dissolve. Mix together the two solutions; dilute to 1 liter with distilled water. Add 1 M sodium hydroxide solution dropwise until the solu- tion’s color is dark green; stir. (Use: pH indicator, pH 4 = red, pH 5 = orange, pH 6=yellow,pH7=lightgreen,pH8= green-blue, pH 9 = dark blue-green, pH 10 = purple)
Winkler’s Solution #1
Dissolve 480 g of manganese (II) sulfate tetrahydrate in 500 mL of DI water, then dilute to 1 L. (determining dissolved oxygen)
Winkler’s Solution #2
Dissolve 500 g of sodium hydroxide and 135 g of sodium iodide in 700 mL of DI water, then dilute to 1 L. A large amount of heat is generated, place the mixing container in an ice water bath. Store in a plastic container. (determining dissolved oxygen)
Wright’s Stain
Dissolve 2.5 g of Wright’s stain in 75 mL of absolute methyl alcohol, then dilute to 100 mL with absolute methyl alcohol. Stir and filter if necessary. (biological stain for blood)
An affordable
milligram balance!
Save time and
improve accuracy
with Flinn’s top-loading milligram balance.
With a capacity of 120 g readabil- ity of 0.001 g and a precision of ±0.002 g it’s perfect for prep rooms and solution making. See flinnsci. com for further details.
Catalog No.
Description
Price/Each
OB2143
Flinn 1 mg Electronic Balance
$447.00