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Biotech Chapter Three Lecture- Basic Lab Skills

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Chapter Three Lecture for CTE Biotechnology on the basic skills of the biotechnology workplace

Chapter Three Lecture for CTE Biotechnology on the basic skills of the biotechnology workplace

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  • 1. The Basic Skills of theBiotechnology WorkplaceChapter 3
  • 2. Learning Outcomes
  • 3. Learning Outcomes Determine the most appropriate tool for measuring specific volumes of masses
  • 4. Learning Outcomes Determine the most appropriate tool for measuring specific volumes of masses Describe how to select, set, and use a variety of micropipets within their designated ranges to accurately measure small volumes
  • 5. Learning Outcomes Determine the most appropriate tool for measuring specific volumes of masses Describe how to select, set, and use a variety of micropipets within their designated ranges to accurately measure small volumes Convert between units of measure using the B S rule and appropriate conversion factors
  • 6. Learning Outcomes
  • 7. Learning Outcomes Recognize the different expressions for units of concentration measurements and use their corresponding equations to calculate the amount of solute needed to make a specified solution
  • 8. Learning Outcomes Recognize the different expressions for units of concentration measurements and use their corresponding equations to calculate the amount of solute needed to make a specified solution Describe what pH is and why it is important in solution preparation
  • 9. 3.1 Measuring Volumes in a Biotechnology Facility
  • 10. 3.1 Measuring Volumes in a Biotechnology FacilityVolume is a measurement of the amount of spacesomething occupies
  • 11. 3.1 Measuring Volumes in a Biotechnology FacilityVolume is a measurement of the amount of spacesomething occupies
  • 12. 3.1 Measuring Volumes in a Biotechnology FacilityVolume is a measurement of the amount of spacesomething occupiesVolume is measured in • Liters (L) • Milliliters (mL) • Microliters (µL)
  • 13. 3.1 Measuring Volumes in a Biotechnology FacilityVolume is a measurement of the amount of spacesomething occupiesVolume is measured in • Liters (L) • Milliliters (mL) • Microliters (µL)Different tools are used to measure volume • Graduated cylinder • Pipet • Micropipet
  • 14. Converting UnitsOften volumes are measured in one unit ofmeasurement and reported in another
  • 15. Converting UnitsOften volumes are measured in one unit ofmeasurement and reported in another •Converting between metric units
  • 16. Converting UnitsOften volumes are measured in one unit ofmeasurement and reported in another •Converting between metric units move decimal point
  • 17. Converting UnitsOften volumes are measured in one unit ofmeasurement and reported in another •Converting between metric units move decimal point B S
  • 18. Converting UnitsOften volumes are measured in one unit ofmeasurement and reported in another •Converting between metric units move decimal point B S •Use a conversion factor for non-metric
  • 19. To measure volumes largerthan 10 milliliters, technicians usually use a graduated cylinder Reading a graduated cylinder. Before using a graduated cylinder, make sure you know the total volume it will hold and the value of each of the graduations.
  • 20. A volumetric flask is a more precise choice will only measure one quantity
  • 21. Using Pipets •Measuring units smaller than 10 mL requires a pipet. • “Never mouth pipet!”25-, 10-, 5-, and 1-mL SEROLOGICAL VOLUMETRIC pipets pipets = better accuracy = pretty accurate
  • 22. Using Micropipets When measuring tiny volumes, less that 1 mL, a micropipet is used. Picking and Using the Appropriate Micropipet•P-100 or P-200 micropipet•P-10 or P-20 micropipet•P-1000 micropipet
  • 23. A micropipet has four parts• Plunger button• Ejector button• Volume display• Dispensing tip
  • 24. Learning to use each part of amicropipet correctly is essential.Inaccurate measurement couldwaste costly reagents and cause invalid experiment results.
  • 25. On the micropipet shown, the plunger has two “stops.”
  • 26. On the micropipet shown, the plunger has two “stops.”Pressing to the first stop evacuates air to the volume in the display. Used for drawing liquid.
  • 27. On the micropipet shown, the plunger has two “stops.” Pressing to the first stop evacuates air to the volume in the display. Used for drawing liquid. Pressing to the second stop evacuatesthat volume plus another 50% or so. Used to dispense.
  • 28. On the micropipet shown, the plunger has two “stops.” Pressing to the first stop evacuates air to the volume in the display. Used for drawing liquid. Pressing to the second stop evacuatesthat volume plus another 50% or so. Used to dispense.To ensure accurate measurement, feel the difference between the first and second stop before using the pipet.
  • 29. P-1000 Micropipet. 100- 1000 µL (1 mL)large tips are usually blue or white in color.
  • 30. P-100 Micropipet. 10 - 100 µL precision to 0.2 µL yellow tips
  • 31. P-10 Micropipet. P-10 micropipets arecommon in biotechnology labs. 0.5 - 10.0 µL precision to 0.02 µL.tiny tips are usually white
  • 32. Picking and Using the Appropriate MicropipetAlways use thesmallest devicepossible.
  • 33. A multichannel pipet allows several samples to be measured at the same time, a feature that saves time during an experiment with multiple replications and repetitive pipeting.
  • 34. Vocabulary
  • 35. Vocabulary• Volume – a measurement of the amount of space something occupies
  • 36. Vocabulary• Volume – a measurement of the amount of space something occupies• Mass – the amount of matter (atoms and molecules) an object contains
  • 37. Vocabulary• Volume – a measurement of the amount of space something occupies• Mass – the amount of matter (atoms and molecules) an object contains• Liter – abbreviated “L”; a unit of measure for volume, approximately equal to a quart
  • 38. Vocabulary• Volume – a measurement of the amount of space something occupies• Mass – the amount of matter (atoms and molecules) an object contains• Liter – abbreviated “L”; a unit of measure for volume, approximately equal to a quart• Milliliter – abbreviated “mL”; a unit of measure for volume; one one-thousandth of a liter (0.001 L) or about equal to one-half teaspoon
  • 39. Vocabulary• Volume – a measurement of the amount of space something occupies• Mass – the amount of matter (atoms and molecules) an object contains• Liter – abbreviated “L”; a unit of measure for volume, approximately equal to a quart• Milliliter – abbreviated “mL”; a unit of measure for volume; one one-thousandth of a liter (0.001 L) or about equal to one-half teaspoon• Microliter – abbreviate “µL”; a unit of measure for volume; equivalent to one-thousandth of a milliliter or about the size of the tiniest teardrop
  • 40. Vocabulary• Volume – a measurement of the amount of space something occupies• Mass – the amount of matter (atoms and molecules) an object contains• Liter – abbreviated “L”; a unit of measure for volume, approximately equal to a quart• Milliliter – abbreviated “mL”; a unit of measure for volume; one one-thousandth of a liter (0.001 L) or about equal to one-half teaspoon• Microliter – abbreviate “µL”; a unit of measure for volume; equivalent to one-thousandth of a milliliter or about the size of the tiniest teardrop• Graduated cylinder – a plastic tube with marks (or graduations) equally spaced to show volumes; measurements are made at the bottom of the meniscus, the lowest part of the concave surface of the liquid in the cylinder
  • 41. Vocabulary
  • 42. Vocabulary • Pipet – an instrument usually used to measure volumes between 0.1 mL and 50 mL
  • 43. Vocabulary • Pipet – an instrument usually used to measure volumes between 0.1 mL and 50 mL • Micropipet – an instrument used to measure very tiny volumes, usually less than a milliliter
  • 44. Vocabulary • Pipet – an instrument usually used to measure volumes between 0.1 mL and 50 mL • Micropipet – an instrument used to measure very tiny volumes, usually less than a milliliter • Unit of measurement – the form in which something is measured (g, mg, µg, L, mL, µL, km, cm, etc.)
  • 45. Vocabulary • Pipet – an instrument usually used to measure volumes between 0.1 mL and 50 mL • Micropipet – an instrument used to measure very tiny volumes, usually less than a milliliter • Unit of measurement – the form in which something is measured (g, mg, µg, L, mL, µL, km, cm, etc.) • Conversion factor – a number (a fraction) where the numerator and denominator are equal to the same amount; commonly used to convert from one unit to another
  • 46. Vocabulary • Pipet – an instrument usually used to measure volumes between 0.1 mL and 50 mL • Micropipet – an instrument used to measure very tiny volumes, usually less than a milliliter • Unit of measurement – the form in which something is measured (g, mg, µg, L, mL, µL, km, cm, etc.) • Conversion factor – a number (a fraction) where the numerator and denominator are equal to the same amount; commonly used to convert from one unit to another • Metrics conversion table – a chart that shows how one unit of measure relates to another (for example, how many milliliters are in a liter)
  • 47. 3.1 Review Questions 0 0 0
  • 48. 3.1 Review Questions1. What instrument would you use to measure and dispense the following volumes? Pick the instrument that is likely to give you the least error for each measurement. 0 0 0
  • 49. 3.1 Review Questions1. What instrument would you use to measure and dispense the following volumes? Pick the instrument that is likely to give you the least error for each measurement.23.5µL 6.5mL 125mL 7µL 2.87mL 555µL 0 0 0
  • 50. 3.1 Review Questions1. What instrument would you use to measure and dispense the following volumes? Pick the instrument that is likely to give you the least error for each measurement.23.5µL 6.5mL 125mL 7µL 2.87mL 555µL2. Convert the following units to the requested unit: 0 0 0
  • 51. 3.1 Review Questions1. What instrument would you use to measure and dispense the following volumes? Pick the instrument that is likely to give you the least error for each measurement.23.5µL 6.5mL 125mL 7µL 2.87mL 555µL2. Convert the following units to the requested unit: 1.7 L = _____ mL 235.1 µL = _____ mL 0 0 0
  • 52. 3.1 Review Questions1. What instrument would you use to measure and dispense the following volumes? Pick the instrument that is likely to give you the least error for each measurement.23.5µL 6.5mL 125mL 7µL 2.87mL 555µL2. Convert the following units to the requested unit: 1.7 L = _____ mL 235.1 µL = _____ mL 2.37 mL = _____ µL 0 0 0
  • 53. 3.1 Review Questions1. What instrument would you use to measure and dispense the following volumes? Pick the instrument that is likely to give you the least error for each measurement.23.5µL 6.5mL 125mL 7µL 2.87mL 555µL2. Convert the following units to the requested unit: 1.7 L = _____ mL 235.1 µL = _____ mL 2.37 mL = _____ µL3. What numbers should be dialed into a P-10 display if a volume of 3.7 µL is to be measured? 0 0 0
  • 54. 3.1 Review Questions1. What instrument would you use to measure and dispense the following volumes? Pick the instrument that is likely to give you the least error for each measurement.23.5µL 6.5mL 125mL 7µL 2.87mL 555µL2. Convert the following units to the requested unit: 1.7 L = _____ mL 235.1 µL = _____ mL 2.37 mL = _____ µL3. What numbers should be dialed into a P-10 display if a volume of 3.7 µL is to be measured? 0 0 04. What instrument should be used if a technician wants to fill 40 sets of 16 tubes all with identical volumes?
  • 55. 3.2 Making Solutions• Solution preparation is one of the most essential skills of a biotechnology lab employee.
  • 56. 3.2 Making Solutions• Solution preparation is one of the most essential skills of a biotechnology lab employee.• Solutions are mixtures in which one or more substances are dissolved in another substance.
  • 57. 3.2 Making Solutions• Solution preparation is one of the most essential skills of a biotechnology lab employee.• Solutions are mixtures in which one or more substances are dissolved in another substance.• Solid solutes are measured on balances or scales.
  • 58. 3.2 Making Solutions• Solution preparation is one of the most essential skills of a biotechnology lab employee.• Solutions are mixtures in which one or more substances are dissolved in another substance.• Solid solutes are measured on balances or scales.• Concentration is measured in several ways: •Mass/volume ●Volume/volume •% mass or % volume ●Molarity •Normality
  • 59. 3.2 Making SolutionsTo make any solution-1) calculate quantity of solute needed for desired amount of solution. amount of solution x concentration = amount of solute (if units agree)
  • 60. 3.2 Making SolutionsTo make any solution-1) calculate quantity of solute needed for desired amount of solution. amount of solution x concentration = amount of solute (if units agree)2) Measure amount of solute
  • 61. 3.2 Making SolutionsTo make any solution-1) calculate quantity of solute needed for desired amount of solution. amount of solution x concentration = amount of solute (if units agree)2) Measure amount of solute3) Add solvent to desired volume
  • 62. 3.2 Making SolutionsTo make any solution-1) calculate quantity of solute needed for desired amount of solution. amount of solution x concentration = amount of solute (if units agree)2) Measure amount of solute3) Add solvent to desired volume4) All measuring devices must be clean (rinsed with deionized water) and completely dry OR rinsed with the material to be measured.
  • 63. 3.2 Making SolutionsTo make any solution-1) calculate quantity of solute needed for desired amount of solution. amount of solution x concentration = amount of solute (if units agree)2) Measure amount of solute3) Add solvent to desired volume4) All measuring devices must be clean (rinsed with deionized water) and completely dry OR rinsed with the material to be measured.Dirty glassware will contaminate/increase solute.Wet glassware will dilute the solution.
  • 64. 3.3 Mass/Volume SolutionsConcentration is measured in several ways:Mass/volume
  • 65. 3.3 Mass/Volume SolutionsConcentration is measured in several ways:Mass/volume •Do concentration calculations to determine the amount of solute required to produce a certain volume. Ex. 200ml of a 5g/L solution requires 5g/L x .2L = 1g solute
  • 66. 3.3 Mass/Volume SolutionsConcentration is measured in several ways:Mass/volume •Do concentration calculations to determine the amount of solute required to produce a certain volume. Ex. 200ml of a 5g/L solution requires 5g/L x .2L = 1g solute •Measure desired mass of solute using a balance
  • 67. 3.3 Mass/Volume SolutionsConcentration is measured in several ways:Mass/volume •Do concentration calculations to determine the amount of solute required to produce a certain volume. Ex. 200ml of a 5g/L solution requires 5g/L x .2L = 1g solute •Measure desired mass of solute using a balance •Add solvent to desired volume
  • 68. Mass/Volume Solution. Solvent is added to 10g proteinuntil a volume of 10 mL is reached. A protein solution that has a concentration of 1 g/mL is considered fairly concentrated.
  • 69. An electronicbalance is good for measuring 1-200 grams.
  • 70. Most analytical balances measuredown to milligrams, even though they usually report in grams.
  • 71. 3.2 Review Questions1. What instrument should be used to measure and dispense the following solutes? 3.5 g of salt 6.5 mg of DNA 12.500 g of gelatin
  • 72. 3.2 Review Questions1. What instrument should be used to measure and dispense the following solutes? 3.5 g of salt 6.5 mg of DNA 12.500 g of gelatin2. What happens to the ratio of solute molecules to solvent as a solution becomes more concentrated?
  • 73. 3.2 Review Questions1. What instrument should be used to measure and dispense the following solutes? 3.5 g of salt 6.5 mg of DNA 12.500 g of gelatin2. What happens to the ratio of solute molecules to solvent as a solution becomes more concentrated?3. Which of the following are concentration units? mi/hr g/mL mM °F/°C
  • 74. 3.2 Review Questions1. What instrument should be used to measure and dispense the following solutes? 3.5 g of salt 6.5 mg of DNA 12.500 g of gelatin2. What happens to the ratio of solute molecules to solvent as a solution becomes more concentrated?3. Which of the following are concentration units? mi/hr g/mL mM °F/°C4. Describe how glassware should be prepared before using it to prepare or store solutions.
  • 75. 3.3 Review Questions1. Which of the following are mass/volume concentration units? g/mL g/mg L/mg µg/µL g/l m
  • 76. 3.3 Review Questions1. Which of the following are mass/volume concentration units? g/mL g/mg L/mg µg/µL g/l m2. What mass of the protein, gelatin, is needed to make 0.5 L of a 3 g/L gelatin solution?
  • 77. 3.3 Review Questions1. Which of the following are mass/volume concentration units? g/mL g/mg L/mg µg/µL g/l m2. What mass of the protein, gelatin, is needed to make 0.5 L of a 3 g/L gelatin solution?3. What mass of sugar is need to make 25 mL of a 25 mg/mL sugar solution?
  • 78. 3.3 Review Questions1. Which of the following are mass/volume concentration units? g/mL g/mg L/mg µg/µL g/l m2. What mass of the protein, gelatin, is needed to make 0.5 L of a 3 g/L gelatin solution?3. What mass of sugar is need to make 25 mL of a 25 mg/mL sugar solution?4. What mass of salt is needed to make 150 mL of a 100 µg/mL salt solution? Describe how the solution is prepared.
  • 79. 3.4- v/v and w/w solutionsConcentration is measured in several ways:Volume/volume
  • 80. 3.4- v/v and w/w solutionsConcentration is measured in several ways:Volume/volume1) calculate solute amount 2 liters of a 20ml/L solution requires 40ml of solute (2L x 20ml/L = 40ml)
  • 81. 3.4- v/v and w/w solutionsConcentration is measured in several ways:Volume/volume1) calculate solute amount 2 liters of a 20ml/L solution requires 40ml of solute (2L x 20ml/L = 40ml)2) Measure solute with cylinder or pipet.
  • 82. 3.4- v/v and w/w solutionsConcentration is measured in several ways:Volume/volume1) calculate solute amount 2 liters of a 20ml/L solution requires 40ml of solute (2L x 20ml/L = 40ml)2) Measure solute with cylinder or pipet.3) Add solvent to final volume (1960ml)
  • 83. 3.4- v/v and w/w solutionsConcentration is measured in several ways:% mass or % volume
  • 84. 3.4- v/v and w/w solutionsConcentration is measured in several ways:% mass or % volumeA %(v/v) solution is made the same as a volume/volume solution, but concentration is expressed asa percent.
  • 85. 3.4- v/v and w/w solutionsConcentration is measured in several ways:% mass or % volumeA %(v/v) solution is made the same as a volume/volume solution, but concentration is expressed asa percent.A 20ml/L solution is 20ml/1000ml, which is 0.02or 2%(v/v).
  • 86. 3.4- v/v and w/w solutionsConcentration is measured in several ways:% mass or % volumeA %(v/v) solution is made the same as a volume/volume solution, but concentration is expressed asa percent.A 20ml/L solution is 20ml/1000ml, which is 0.02or 2%(v/v).A %(w/w) solution is very similar but solute &solvent must be weighed.
  • 87. 3.4 Review Questions1. What is the decimal equivalent of the following percentages? 10% 15% 25% 2% 1.5% 0.5%
  • 88. 3.4 Review Questions1. What is the decimal equivalent of the following percentages? 10% 15% 25% 2% 1.5% 0.5%2. What mass of gelatin (a protein) is needed to make 0.5 L of a 3% gelatin solution?
  • 89. 3.4 Review Questions1. What is the decimal equivalent of the following percentages? 10% 15% 25% 2% 1.5% 0.5%2. What mass of gelatin (a protein) is needed to make 0.5 L of a 3% gelatin solution?3. What mass of sugar is needed to make 25 mL of a 2.5% sugar solution?
  • 90. 3.4 Review Questions1. What is the decimal equivalent of the following percentages? 10% 15% 25% 2% 1.5% 0.5%2. What mass of gelatin (a protein) is needed to make 0.5 L of a 3% gelatin solution?3. What mass of sugar is needed to make 25 mL of a 2.5% sugar solution?4. What mass of salt is needed to make 150 mL of a 10% salt solution? Describe how the solution is prepared.
  • 91. 3.5 MolarityConcentration is measured in several ways:Molarity = moles/Liter
  • 92. 3.5 MolarityConcentration is measured in several ways:Molarity = moles/Liter1) Determine moles of solute required. Molarity x volume of solution = moles solute 250ml of 2M NaCl needs 0.25L x 2M = 0.5moles NaCl
  • 93. 3.5 MolarityConcentration is measured in several ways:Molarity = moles/Liter1) Determine moles of solute required. Molarity x volume of solution = moles solute 250ml of 2M NaCl needs 0.25L x 2M = 0.5moles NaCl2) Convert moles to grams (multiply by molar mass of solute) 0.5mol NaCl x 58.5g/mol = 29.25g NaCl
  • 94. 3.5 MolarityConcentration is measured in several ways:Molarity = moles/Liter1) Determine moles of solute required. Molarity x volume of solution = moles solute 250ml of 2M NaCl needs 0.25L x 2M = 0.5moles NaCl2) Convert moles to grams (multiply by molar mass of solute) 0.5mol NaCl x 58.5g/mol = 29.25g NaCl3) Mass required amount of solute.
  • 95. 3.5 MolarityConcentration is measured in several ways:Molarity = moles/Liter1) Determine moles of solute required. Molarity x volume of solution = moles solute 250ml of 2M NaCl needs 0.25L x 2M = 0.5moles NaCl2) Convert moles to grams (multiply by molar mass of solute) 0.5mol NaCl x 58.5g/mol = 29.25g NaCl3) Mass required amount of solute.4) Add solvent to final volume.
  • 96. 3.5 Review Questions1.What is the molecular weight of each of the following compounds? NaOH MgCl2 Mg(OH)2 HCl
  • 97. 3.5 Review Questions1.What is the molecular weight of each of the following compounds? NaOH MgCl2 Mg(OH)2 HCl2. What mass of NaCl is needed for 0.5 L of a 0.5 M NaCl solution?
  • 98. 3.5 Review Questions1.What is the molecular weight of each of the following compounds? NaOH MgCl2 Mg(OH)2 HCl2. What mass of NaCl is needed for 0.5 L of a 0.5 M NaCl solution?3. What mass of MgCl2 is needed for 200 mL of a 0.025 M MgCl2 solution?
  • 99. 3.5 Review Questions1.What is the molecular weight of each of the following compounds? NaOH MgCl2 Mg(OH)2 HCl2. What mass of NaCl is needed for 0.5 L of a 0.5 M NaCl solution?3. What mass of MgCl2 is needed for 200 mL of a . 025 M MgCl2 solution?4. What mass of sodium hydroxide (NaOH) is needed to make 750 mL of a 125 mM NaOH solution? Describe how to prepare the solution.
  • 100. Vocabulary Solution – a mixture of two or more substances where one (solute) completely dissolves in the other (solvent)
  • 101. Vocabulary Solution – a mixture of two or more substances where one (solute) completely dissolves in the other (solvent) Aqueous – describing a solution in which the solvent is water
  • 102. Vocabulary Solution – a mixture of two or more substances where one (solute) completely dissolves in the other (solvent) Aqueous – describing a solution in which the solvent is water Solute – the substance in a solution that is being dissolved
  • 103. Vocabulary Solution – a mixture of two or more substances where one (solute) completely dissolves in the other (solvent) Aqueous – describing a solution in which the solvent is water Solute – the substance in a solution that is being dissolved Balance – an instrument that measures mass
  • 104. Vocabulary Solution – a mixture of two or more substances where one (solute) completely dissolves in the other (solvent) Aqueous – describing a solution in which the solvent is water Solute – the substance in a solution that is being dissolved Balance – an instrument that measures mass Weight – the force exerted on something by gravity; at sea level, it is considered equal to the mass of an object
  • 105. Vocabulary Gram – abbreviated “g”; the standard unit of mass, approximately equal to the mass of a small paper clip
  • 106. Vocabulary Gram – abbreviated “g”; the standard unit of mass, approximately equal to the mass of a small paper clip Solvent – the substance that dissolves the solute
  • 107. Vocabulary Gram – abbreviated “g”; the standard unit of mass, approximately equal to the mass of a small paper clip Solvent – the substance that dissolves the solute Molarity – a measure of concentration that represents the number of moles of a solute in a liter of solution (or some fraction of that unit)
  • 108. Vocabulary Gram – abbreviated “g”; the standard unit of mass, approximately equal to the mass of a small paper clip Solvent – the substance that dissolves the solute Molarity – a measure of concentration that represents the number of moles of a solute in a liter of solution (or some fraction of that unit) Normality – a measurement of concentration generally used for acids and bases that represents the amount of ionization of an acid or base. 2M HCl = 2N HCl 2M H2SO4 = 4N H2SO4
  • 109. VocabularyPercentage – a proportion of something out of100 parts, expressed as a whole number20/100 = 0.2 = 20% Mole – the mass, in grams, of 6 X 1023 atoms of molecules of a given substance; one mole is equivalent to the molecular weight of a given substance, reported in grams Molecular weight – the sum of all the atomic weights of the atoms in a given molecule Mass spectrometer – an instrument that is used to determine the molecular weight of a compound
  • 110. This instrument is a mass spectrometer. Scientists use it to determine the molecular weight of a compound.A “mass spec” can also determine if a sample is contaminated with molecules of different molecular weights.
  • 111. 3.6 Dilutes of Concentrated Solutions Many chemical and biological reagents are purchased in concentrated form.
  • 112. 3.6 Dilutes of Concentrated Solutions Many chemical and biological reagents are purchased in concentrated form. Concentrated solutions can be prepared initially with a greater amount of solute to solvent, or a solution can be concentrated by removing water.
  • 113. 3.6 Dilutes of Concentrated Solutions Many chemical and biological reagents are purchased in concentrated form. Concentrated solutions can be prepared initially with a greater amount of solute to solvent, or a solution can be concentrated by removing water. A diluted solution can be prepared by adding solvent to a concentrated one.
  • 114. 3.6 Dilutes of Concentrated Solutions Concentrationstock x Volumestock =Concentrationdiluted x Volumediluted CsVs = CdVd Solve for the volume of stock solution needed
  • 115. Diluting a 100 mg/mL Stock Solution to make 1L of 1 mg/mL. 100 mg/mL x Vs = 1 mg/mL x 1000mL need 10 ml of stock
  • 116. Vocabulary Dilution – the process in which solvent is added to make a solution less concentrated
  • 117. Vocabulary Dilution – the process in which solvent is added to make a solution less concentrated Stock solution – a concentrated form of a reagent that is often diluted to form a “working solution”
  • 118. Vocabulary Dilution – the process in which solvent is added to make a solution less concentrated Stock solution – a concentrated form of a reagent that is often diluted to form a “working solution” Buffer – a solution that acts to resist a change in pH when the hydrogen ion concentration is changed
  • 119. Vocabulary Dilution – the process in which solvent is added to make a solution less concentrated Stock solution – a concentrated form of a reagent that is often diluted to form a “working solution” Buffer – a solution that acts to resist a change in pH when the hydrogen ion concentration is changed TRIS – a complex organic molecule used to maintain the pH of a solution
  • 120. 3.6 Review Questions1. How do you prepare 40 mL of a 2 mg/mL protein solution from 10 mg/mL protein solution?
  • 121. 3.6 Review Questions1. How do you prepare 40 mL of a 2 mg/mL protein solution from 10 mg/mL protein solution?2. How do you prepare 200 µL of 2X enzyme buffer from 10X enzyme buffer solution?
  • 122. 3.6 Review Questions1. How do you prepare 40 mL of a 2 mg/mL protein solution from 10 mg/mL protein solution?2. How do you prepare 200 µL of 2X enzyme buffer from 10X enzyme buffer solution?3. How do you prepare 500 µL of 10 µM NaCl solution from 5 µM NaCl solution?
  • 123. 3.6 Review Questions1. How do you prepare 40 mL of a 2 mg/mL protein solution from 10 mg/mL protein solution?2. How do you prepare 200 µL of 2X enzyme buffer from 10X enzyme buffer solution?3. How do you prepare 500 µL of 10 µM NaCl solution from 5 µM NaCl solution?4. How do you prepare 3 L of 1X TAE buffer from 50X TAE buffer stock solution?