Transcript Mass Spectrometry

Mass Spectrometry
Week 2 Lab
S117 Fall 2011
Overview
• Post-Lab: Percent Alcohol in Wine
– TurnItIn.com
– Working with data sets
– Analyzing data sets
– Analysis of experimental procedure
• Pre-lab: Mass Spectrometry
– Fragmentation
– Protein Analysis
• Practical matters of lab meeting
Assignments
• Sign up for turnitin.com
• Formal reports due electronically up to time of
lab
• One minute24 hours late = 20pt penalty
• Give copy of lab notebook to AI in lab
Excel
• Working with data sets
• Statistical Analysis
• Certainty and uncertainty
– Measurements
– Experimental limit
– Reproducibility
Experimental Design
• Practical Weaknesses?
• Propagation of Error
• Was the distillation
useful?
Pre-Lab: Mass Spectrometry
Analysis of isotopes!
Inlet System
Ion Source
Mass
Analyzer
Vacuum (10-5 10-8 torr) r
Detector
Nominal Mass and Exact Mass
• Nominal Mass: Low resolution
–
–
–
35Cl
= 35 Da
37Cl = 37 Da
CO = N2 = 28 Da
• Exact Mass: High Resolution
–
–
CO = 27.9949 Da
N2 = 28.0061 Da
Analysis of Molecules
• Parent peak (molecular ion)and fragment
peaks
• Analysis of fragment patterns useful
• Application to Cl2
isovaleraldehyde
caffeine
Analysis of Biomolecules
• Complex
molecules
• Molecular mass
in kiloDaltons
(kDa)
• Nobel Prizes for
MS of proteins
Proteins Made of Amino Acids
Mass Spec and Mutations
• Sickle Cell
Anemia
• Point
Mutation
• How can
MS be
used to
identify
Mutations?
Identification of Proteins
• Comparison of 2D electrophoresis
Identification of Proteins
Purified
Protein
Trypsin
Digest
Mix of
Peptides
Example 1
ASRLVMKQQKD
Example 2
ASRLVKMQKQD
ASR LVMK
QQK D
Mass
Spec
Mass Data
of mixture
MS
Library
Identity of
Protein
Practical Matters
•
•
•
•
Meet in chemistry computer lab 006
Mass Spec lab tours
Dry lab: No special clothing requirements!
Remember formal report and lab notebook