How to write a lab report on identification of unknown bacteria

Biology 225
Sections of the report
 Title
 Introduction
 Materials and Methods
 Results
 Discussion
 Conclusions
 References
Purpose: To accurately describe the scope of your
 Be descriptive
 Include your tube #
Example: The identification of two unknown species of
bacteria in tube #99
Purpose: To introduce your project to the reader and tell
how this work would be accomplished and its
 Includes the question that began this whole process
 Includes HOW you were going to answer the question
 Possible species
 Possible tests, stains, etc.
 Possible techniques that could have been used
 Includes the reasons that this type of experiment is
Materials and Methods
Purpose: To tell the reader what you did and how
 Describe what you did
 Do not include dates
 Reference your lab manual – this is how you knew what to
 Do not forget time and temperature of incubation of
biochemical tests
 Do not repeat yourself
 Do not list the materials
Purpose: To represent your data/results in the best possible
 Represent your data in tables and figures
 Tables and figures are “pictures” of your data that are easily read
and understood
Do not write out all of your results in paragraph form
Captions are crucial!
Caption = descriptive title that allows that table or figure to be
understood by anyone, even outside of the original paper
Figures are drawings, pictures, graphs – anything except tables
Example of Table
Stains, tests,
Gram + species
Gram - species
Cell shape
Cell arrangement
Incubation temperature
25 C
37 C
Colony morphology
Yellow, shiny, round
Beige, shiny, oblong
Example of caption for table
 Table 1 – Cell and colony characteristics, staining
characteristics, and biochemical test results from the
identification of Gram + and Gram – bacteria in tube
Purpose: To describe to the reader what your logic was
behind the choice of the two species that you identified
 Explain your elimination process – how did you
eliminate 8 of 10 possible species of bacteria
 Discuss one of your species at a time
 Show how the characteristics of your species are
related to the results of tests that you had
 Discuss any problems that occurred and give possible
causes for those problems
Purpose: To state the identity of your unknowns
 A one or two sentence statement telling what the
identity of your two unknown species of bacteria were.
Lab manual
Personal communications
Bergey’s Manual…
Your textbook
Websites – use complete URL
Other sources
References should be listed in numerical order that they
were used in the report.
 Superscript numbers are used at the end of sentences were
you used references.
General tips….
 Write in the past tense – this is what you did
 Do not use personal pronouns….I, you, etc.
 This is a scientific paper. Be concise and to-the-point.
 Cover all information adequately.
More general tips….
 Use white paper and black ink
 Use reasonable margins and font
 Put your name somewhere on the report
 NO cover or coversheet
 Length – long enough to get the job done
How to get started
 Writing is hard!
 Start with what you know best – your Materials and
Methods section
 Then continue on with your Results section
 Write your Discussion section next
 Then finish with the rest of the sections
 Gradesheet in D2L
 10 points for correctly identifying your two species
 Results = 20 points
 Discussion = 25 points (THE most important section)
 Minimum score of 70% to finish the course
 Late point deduction = -10 points per day late
The End