1. General Information Instructor: John Basso
Tel Ext. 6358
Office: BSC102
My web page :
Course’s web page:

2. My Web Page

3. Grading Quiz – 5% Each week
Available on Brightspace Saturday 9 am to Sunday 9 am
30 minutes
2% bonus for 100% on at least 4 of the 8 quizzes
Quiz 1 Saturday January 13th

4. Grading Assignments X 5 - 25%
Submitted individually or in groups of two
Part I: Theory
Part II:
Data analysis
Lab performance
Submit your own results
Part III: Bioinformatics

5. Grading Exams Open book Access to the internet is allowed for midterm
Use of laptops is not allowed
Must use lab computers

6. Grading Midterm – 10-25% 2 hours 5 calculation problems (5 points)
5 bioinfo exercises (5 points)
5 theoretical questions on bioinfo and molecular procedures (5 points)
2 out of 3 problems on data analysis and experimental design (10 points)

7. Grading Final exam – 45-60% Cumulative 4 hours Part I – 1.5 hours
10 bioinfo exercises (10 points)
Part II – 2.5 hours
10 calculation problems (10 points)
5 theoretical questions on bioinfo and molecular procedures (5 points)
3 out of 4 problems with an emphasis on data analysis and experimental design (15 points)

8. Grading Quiz 5% + *Bonus 2% Assignments (X5) 25% Midterm exam 10%
Option I
Option II
Quiz
5% + *Bonus 2%
Assignments (X5)
25%
Midterm exam
10%
Final exam
45%
60%
Total
102%

9. Obtaining your data You must have a USB key to save your pictures
Absorbance readings will be available on the web
It is recommended that you have a note book

10. Working with Solutions

11. Definitions
Solution
Mixture of 2 or more ingredients in a single phase
Solutions are composed of two constituents
Solute (ingredient)
A solid that is being dissolved
Or a stock solution that is being diluted
Solvent (OR Diluent)
Part of solution in which solute is dissolved or stock solution is being diluted

12. Preparing solutions 2 ways to create a solution By dissolving a solid
By diluting a more concentrated solution
Do your calculations
Final volume required
Mass of solid (solutes)
Volume of stock solutions
Volume of solvant
 Add solvent first (usually water)
Add other ingredients to solvent
If enzymes are required add last

13. Measuring small volumes - Micropipetting
Allows to measure microliters (µL)
1 000 X less than 1 milliliter
2-20 µL µL µL
Max mL 0.2mL 1mL

14. Setting the volume- P20 Tens (0, 1=10 or 2=20) Units (0-9)
Decimal (1-9 = )

15. Setting the volume- P200 Hundreds (0, 1=100 or 2=200)
Tens (0, 1-9=10-90)
Units (1-9)

16. Setting the volume- P1000 Thousands (0, 1=1000)
Hundreds (0, 1-9= )
Tens (0, 1-9= )

17. Using the micropipettor
Step 1
Insert tip
Step 3
Insert tip in solution to be drawn
Step 4
Draw up sample by
slowly releasing plunger
Step 2
Press plunger
up to first stop
Step 5
Withdraw pipettor

18. Dispensing
Start dispensing 1st stop =Dispense 2nd stop = Expel

19. Guidelines for optimal reproducibility
Use pipettor whose volume is closest to the one desired
Consistent SPEED and SMOOTHNESS to press and release the PLUNGER
Consistent IMMERSION DEPTH
3-4mm below surface
AVOID air bubbles
NEVER go beyond the limits of the pipettor

20. Preparing solutions
Working with concentrations
Dilutions
Amounts

21. Concentrations Concentration = Quantity of solute
Quantity of solution (Not solvent)
Common ways to express concentrations:
Molar concentration (Molarity)
Percentages
Mass per volume
Ratios

22. Molarity # of Moles of solute/Liter of solution
Mass of solute: given in grams (g)
Molecular weight (MW): given in grams per mole (g/mole)
Moles of solute =
Mass of solute
MW of solute
Molarity =
Moles of solute
Volume in L of solution

23. Percentages Percentage concentrations can be expressed as either:
V/V – volume (mL) of solute/100 mL of solution
M/M – Mass of solute (g) /100 g of solution
M/V – Mass of solute (g) /100 mL of solution
All represented as fractions of 100

24. Percentages (Cont’d) %V/V %M/V % M/M
Ex. 4.1L solute/55L solution =7.5%
Must have same units top and bottom!
%M/V
Ex. 16g solute/50mL solution =32%
Must have units of same order of magnitude top and bottom!
% M/M
Ex. 1.7g solute/35g solution =4.9%

25. Mass per volume A mass (amount) per a volume Ex. 1kg/L
Know the difference between an amount and a concentration!
In the above example 1 litre contains 1kg (an amount)
What amount would be contained in 100ml?
What is the percentage of this solution?

26. Ratios
A way to express the relationship between different constituents
Expressed according to the number of parts of each component
Ex. 24 ml of chloroform + 25 ml of phenol + 1 ml isoamyl alcohol
Therefore 24 parts + 25 parts + 1 part
Ratio: 24:25:1
How many parts are there in this solution?

27. Dilutions: Reducing a Concentration A Fraction
Preparing solutions
Dilutions: Reducing a Concentration
A Fraction

28. Dilutions Dilution = making weaker solutions from stronger ones
Example: Making orange juice from frozen concentrate. You mix one can of frozen orange juice with three (3) cans of water.

29. Dilutions (cont’d)
Dilutions are expressed as the volume of the solution being diluted per the total final volume of the dilution
In the orange juice example, the dilution would be expressed as 1/4, for one can of O.J. to a TOTAL of four cans of diluted O.J. When saying the dilution, you would say, in the O.J. example: “one in four”.

30. Dilutions (cont’d) Another example:
If you dilute 1 ml of serum with 9 ml of saline, the dilution would be written 1/10 or said “one in ten”, because you express the volume of the solution being diluted (1 ml of serum) per the TOTAL final volume of the dilution (10 ml total).

31. Dilutions (cont’d) Another example:
One (1) part of concentrated acid is diluted with 100 parts of water. The total solution volume is 101 parts (1 part acid parts water). The dilution is written as 1/101 or said “one in one hundred and one”.

32. Dilutions (cont’d)
Notice that dilutions do NOT have units (cans, ml, or parts) but are expressed as the number parts to the total number of parts
Dilutions are always expressed as a fraction of one
1 part / total number of parts
Example: 1/10 or “one in ten”
OR: 1/(1+9)
OR 1 part solute/1 part solute + 9 parts solvent

33. Dilutions (cont’d)
Dilutions are always expressed with the original substance being diluted as one (1). If more than one part of original substance is initially used, it is necessary to convert the original substance part to one (1) when the dilution is expressed.

34. Dilutions (cont’d) Example:
Two (2) parts of dye are diluted with eight (8) parts of solvant. The total solution volume is 10 parts (2 parts dye + 8 parts diluent). The dilution is initially expressed as 2/10, but the original substance must be expressed as one (1). To get the original volume to one (1), use a ratio and proportion equation, remembering that dilutions are stated in terms of 1 to something:
______2 parts dye = ___1.0___
10 parts total volume x
2 x =
x =
The dilution is expressed as 1/5.

35. Problem Two parts of blood are diluted with five parts of saline
What is the dilution?
10 ml of saline are added to 0.05 L of water
2/(2+5) = 2/7 =1/3.5
10/(10+50) = 10/60=1/6

36. Working with parts
Preparation of 110 mL solution representing a 1/10 dilution
1/10th of final volume must be stock solution
9/10th of final volume must be solvent
1/10th of 110 mL = 11 mL = 1 part
9/10th of 110 mL = 99 mL = 9 parts

37. Working with parts
A solution is prepared by adding 15 mL of a stock solution to 75 mL of solvent. What is the dilution and the volume of 1 part?
Volume of one part
Fraction: 15mL stock/(15mL stock + 75mL solvent)
= 15/90 = 1/6 dilution
Solution is therefore composed of a total of 6 parts
Total number of parts = 6 = 90 mL
One part = 90 mL/6 = 15 mL

38. Problem : More than one ingredient
Want to prepare 25 mL of a solution containing two ingredients (solutes)
Need the following dilutions
Solute “a”: 1/10
Solute “b”: 1/3

39. Problem: More than one ingredient
Express each ingredient being diluted over the same common denominator!
Solute « a » : 1/10 = 1.5/15
Solute « b » : 1/3 = 5/15
Therefore need 1.5 parts of solute “a” + 5 parts of solute “b” parts of solvent
Thus a total of 6.5 parts solute/15 parts solution
15 parts of solution = 25mL, thus 1 part = 1.67 mL
Need 1.5 parts of solute “a” :1.5 X 1.67 mL = 2.51 mL
Need 5 parts of solute “b”: 5 X 1.67 mL = 8.35 mL
Need 8.5 parts of solvent: 8.5 X 1.67 mL = mL

40. Determining the Required Fraction: The Dilution
What I have
What I want
Determine the reduction factor
(The dilution factor) =
Ex. You have a solution at 25 mg/ml and want to obtain a solution at 5mg/ml
Therefore the reduction factor is: mg/ml
5mg/ml =
5 (Dilution factor)
The fraction is equal to 1/the dilution factor = 1/5 (the dilution)

41. Determining the Volumes Required
Ex. You want 55 mL of a solution which represents a 1/5 dilution
Use a ratio equation:
1/5 = x/55 = 11/55
Therefore 11 mL of stock/ (55 mL – 11 mL) of solvent
= 11 ml of stock/ 44 ml of solvent

42. Problem #1 Prepare 25mL of a 2mM solution from a stock of 0.1M
What is the dilution required?
What volumes of solvent and stock solution are required?
2mM/100mM =1/50

43. Problem #2
What volume of a 0.1M stock solution should be added to 25 mL of water to obtain a 2mM final concentration ?
What is the dilution required?
Volumes of solute required?
2mM/100mM = 1/50
1/50 dilution = 1 part stock/50 parts solution
= 1 part stock/1 part stock + 49 parts solvent
Volume of solvent = 25 mL = 49 parts
Therefore volume of one part = 25 mL/49 = 0.51mL
0.51/( ) = 0.51/25.51 = 1/50

44. Quantities Quantities are NOT concentrations! Ex 1. Ex 2.
Two apples per bag = a concentration
Two apples = an amount
Ex 2.
10g per 100 mL = a concentration
10g = an amount

45. From concentrations to amounts
The concentration indicates the amount in a given volume
Ex. 1mM = 1 millimole per each liter
Therefore the amount in 1 L is 1 millimole
What volume of solution would you need to have 0.05 millimoles?

46. Ratios
Means of expressing solutions by indicating the ratio between the different components:
Mass ratios
Molar ratios
Volume ratios

47. Mass ratios Ex. 12g of NaCl is dissolved in 1000ml of water
Convert the units so that they are the same
12g of NaCl in 100g of water
Divide the quantities by the value of the smallest quantity
12g/12g : 100g/12g
The ratio
NaCl : water= 1:8.3

48. Molar ratios Ex. 12g of NaCl is dissolved in 100ml water
Convert the units into moles
12g/(58g/mole) of NaCl in 100g/(18g/mole) of water
0.2 moles of NaCl : 5.6 moles of water
Divide the quantities by the value of the smallest quantity
0.2moles/0.2moles : 5.6moles/0.2moles
The ratio
NaCl : water= 1:28

49. Volume ratios Ex. 12ml of alcohol are added to 1L of water
Convert the units so that they are the same
12ml alcohol in 1000ml of water
Divide the qauntities by the value of the smallest quantity
12ml/12ml : 1000ml/12ml
The ratio
Alcohol : water = 1:83.3

50. Densities Densities are not concentrations!
Density expresses the relationship between a mass and the volume it occupies
g/mL
Example: 1g of water occupies a volume of 1 mL
Note: The density of a solute (solid) is not the same as that of a dissolved solute (solution)

51. Densities Example Sample problem: Density of NaCl: 2.16 g/mL
Denisty of 10% NaCl (m/v): 1.07 g/mL
Sample problem:
How much water is there in 100 mL of a 30% (m/v) NaCl solution
30g NaCl /100 ml solution
30g NaCl occupies a volume of mL
Therefore volume of water = 100 – = mL