Phytohemaglutinin (PHA)
Available as kidney bean lectin. It is typically used as a stock solution of 10-20 g/ml in balanced salt solution. For tissue culture it must be cold sterilized prior to use.
Potassium chloride (KCl MW 74.55)
| 1 M | Dissolve 74.55 grams of KCl to a final volume of 1 liter with water or buffer. For other concentrations, multiply the weight by the required molarity. For example, for 0.150 M (150 mM), use 0.150 X 74.55, or 11.183 grams of KCl in 1 liter of water or buffer. Use half as much to obtain 0.075 M for karyotyping. |
Potassium cyanide (KCN MW 65.11)
| 8 mM | Dissolve 52 mg KCN to a final volume of 100 ml with water or buffer. |
Potassium phosphate, monobasic (KH
PO
MW 136.09)
| 0.01M | Dissolve 1.36 grams of monobasic potassium phosphate to a final volume of 1 liter with water. |
Potassium phosphate, dibasic (KHPO MW 174)
| 0.01 M | Dissolve 1.74 grams of dibasic potassium phosphate to a final volume of 1 liter with water. |
Potassium phosphate buffer
| 0.01M pH 7.4 | Prepare 500 ml of 0.01 M KHPO and 500 ml of 0.01 M KHPO Place the K2HPO onto a magnetic stirrer and insert a pH electrode. Ad d the KHPO slowly to adjust the pH to 7.4. |
Potassium hydroxide (KOH MW 56.10)
| 0.5 N | Dissolve 28.05 grams of KOH to a final volume of 1 liter with water. |
| 10% (w/v) | Dissolve 10 grams of KOH to a final volume of 100 ml with water. Store in a plastic container. |
Potassium sodium tartrate (Rochelle salt KNaCH
O · 4HO MW 282.23)
n-Propanol (C
H
OH MW 60.11)
| 3 M | The n-propanol can be weighed (180.3 grams) or measured volumetrically by using the density. That is, 180.3 grams  0.8035 grams/ml or 224.4 ml of n-propanol. Weigh or measure the appropriate amount and dilute to a final volume of 1 liter with water. |
Protein Buffer
Dissolve 1.46 grams of KHPO and 0.92 grams of K2HPO in 80 ml of distilled water. Add 2.5 grams of crystalline serum albumin and adjust the volume to a final 100 ml with water.
Pyronin Y (acetone)
| 0.6% (w/v) | Dissolve 0.6 grams of pyronin Y in 100 ml of acetone. |
Ribonuclease
| 0.1% (w/v) | Dissolve 10 mg of pancreatic ribonuclease type A in 10 ml of water or buffer. Use for enzyme treatment of histological sections by floating 0.5-1.0 ml of this solution onto the section, with the slide set into a covered petri plate. |
Safranin
Dissolve 2.5 grams of Safranin O in 10 ml of 95% ethanol and dilute to 100 ml with water.
Saline (NaCl)
| 0.85% (w/v) | Saline refers to a solution of NaCl, with the most common usage for that which is isotonic to mammalian blood cells, notable a 0.85% or 0.9% solution. To mix, dissolve 8.5 grams of NaCl to a final volume of 1 liter with water. |
Saline citrate (1/10 dilution of SSC)
Dissolve 0.878 grams of NaCl and 0.294 grams of sodium citrate to a final volume of 1 liter with water.
Saline citrate buffer (SSC)
| 20X | It is common to prepare this buffer as a stock 20X solution, to be diluted to 2X, 1X or 0.1X prior to use. To prepare a 20X stock solution, dissolve 175 grams of NaCl and 88 grams of sodium citrate in 900 ml of water. Adjust the pH to 7.0 with 1 N HCl and bring to a final volume of 1 liter. For use, as a 1X SSC, dilute 1 part 20X stock with 19 parts distilled water. For a 2X SSC, dilute 1 part 20X stock with 9 parts water. |
Schiff's Reagent
Dissolve 0.8 grams of basic fuchsin in 85 ml of distilled water. Add 1.9 grams of sodium metabisulfite and 15.0 ml of 1 N HCl. Place the solution in separatory funnel and shake at 2 hour intervals for a period of approximately 12 hours. Add 200 grams of a ctivated charcoal, shake for 1 minute and filter the clear solution. If the solution is still pink, add another 100 grams of charcoal and shake for an additional minute. Filter and store in a dark bottle. Solution should be clear (no pink coloration) for use.
Scott solution
Dissolve 2.0 grams of sodium bicarbonate and 20.0 grams of magnesium sulfate in water to a final volume of 1 liter. Add a pinch of thymol to retard the growth of molds.
SDS
Refer to Sodium lauryl sulfate.
1X SDS-Electrophoresis Running Buffer
Dilute 5X Tris-Glycine buffer to 1X and add 1.0 gram of SDS per liter of 1X Tris-Glycine. The pH should be 8.3 after dilution.
2X SDS Sample Buffer
Dissolve 1.52 grams of Tris base, 2.0 grams of SDS, 20 ml of glycerin, 2.0 ml of -mercaptoethanol and 1 mg of bromophenol blue to a final volume of 100 ml with water.
Siliconized pipettes
Pasteur pipettes can be siliconized by soaking them in a beaker containing 5% (v/v) dichlorodimethylsilane in chloroform for about 1 minute. Remove, drain and rinse several times with distilled water. Bake the pipettes at 180 ° C for 2 hours and cool before use.
Dichlorodimethylsilane and chloroform are both toxic and volatile. Use only in proper fume hood and keep all flames away from work area. Insure that all silicone and chloroform are removed from glassware before placing in an oven.
Silver nitrate solution (for electrophoresis staining)
Dissolve 0.15 grams of NaOH in 150 ml of water. Add 3.5 ml of concentrated NHOH and bring to a volume of 200 ml. Separately, dissolve 2.0 grams of silver nitrate in a final volume of 10 ml. With constant stirring, add 8.0 ml of the silver nitrate to the 200 ml of NaOH/NHOH.
This solution should be prepared immediately prior to use, and used within 30 minutes.
Dispose of this solution with copious flushing. It becomes explosive upon drying.
SM agar medium (Slime Mold medium of Sussman)
Dissolve 10.0 grams of glucose, 10.0 grams of peptone, 1.0 gram of yeast extract, 1.0 gram of MgSO, 1.5 grams of KHPO, 1.0 gram of K2HPO and 20.0 grams of agar to a final volume of 1 liter. Heat to dissolve the agar, autoclave and dispense to petri plates.
Sodium acetate (MW 82.04)
| 1 M | Dissolve 82.04 grams of sodium acetate to a final volume of 1 liter with water or buffer. |
| 0.02 M | Dissolve 1.64 grams of sodium acetate to a final volume of 1 liter with water or buffer. |
Sodium acetate buffer
| 1 M pH 5.7 | To 925 ml of 1 M sodium acetate, add 75 ml of 1 M acetic acid. |
Sodium azide (MW 65.02)
| 0.01 M | Dissolve 0.065 grams of sodium azide to a final volume of 100 ml with water. |
| 0.39% (w/v) | Dissolve 0.39 grams of sodium azide to a final volume of 100 ml with water or buffer. |
Sodium barbitol
| 0.2% (w/v) | Dissolve 0.2 grams of sodium barbitol to a final volume of 100 ml with water. |
Sodium bicarbonate (NaHCO MW 84.0)
| 0.1 M | Dissolve 0.84 grams of NaHCO to a final volume of 100 ml with water or buffer. |
Sodium cacodylate buffer
| 0.2 M pH 7.4 | Prepare a 0.2 M solution of cacodylic acid, sodium salt (MW 159.91). Dissolve 3.20 grams of cacodylic acid, sodium salt to a final volume of 100 ml with water. Adjust the pH to 7.4 with HCL. |
Cacodylic acid contains arsenic. Handle properly.
Sodium carbonate (MW 106.0)
| 2% (w/v) | Dissolve 2.0 grams of sodium carbonate to a final volume of 100 ml with 0.1 N NaOH. |
| 0.1 N NaOH | Used for Lowry Protein assay. |
Sodium chloride (MW 58.44)
| M | For a molar solution of sodium chloride, dissolve 58.44 grams of NaCl to a final volume of 1 liter with water or buffer. For corresponding dilutions, multiply the weight by the molarity required. For example, for 0.05 M, multiply 58.44 by 0.05 or 2.92 grams/liter. |
| % | For % solutions, they are invariably w/v. For a 1 % (w/v) solution, dissolve 1.0 gram of NaCl to a final volume of 100 ml with water or buffer. Multiply the weight by a corresponding change in % for other concentrations. |
| 200,300,400 mOsM | Osmoles for NaCl are calculated as twice the molar concentration. Thus, a 200 mOsM solution would be .100 M NaCl. Likewise, 300 mOsM would be .150 M and 400 mOsM would be .200 M NaCl. |