How to write a lab report on identification of

unknown bacteriaBiology 225

Sections of the reportTitleIntroductionMaterials and MethodsResultsDiscussionConclusionsReferences

TitlePurpose: To accurately describe the scope

of your project

Be descriptiveInclude 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 importance

Includes the question that began this whole processIncludes HOW you were going to answer the

questionPossible speciesPossible tests, stains, etc.Possible techniques that could have been used

Includes the reasons that this type of experiment is important

Introduction

Materials and MethodsPurpose: To tell the reader what you did and how

Describe what you didDo not include datesReference your lab manual – this is how you knew

what to do Do not forget time and temperature of incubation of

biochemical testsDo not repeat yourselfDo not list the materials

ResultsPurpose: To represent your data/results in the best

possible way

Represent your data in tables and figuresTables and figures are “pictures” of your data that are

easily read and understoodDo not write out all of your results in paragraph formCaptions 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 TableStains, tests, characteristics observed

Gram + species Gram - species

Cell shape Coccus Bacillus

Cell arrangement Tetrads Single

Incubation temperature 25 C 37 C

Colony morphology Yellow, shiny, round Beige, shiny, oblong

Etc………

Example of caption for tableTable 1 – Cell and colony characteristics,

staining characteristics, and biochemical test results from the identification of Gram + and Gram – bacteria in tube #99.

DiscussionPurpose: 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 timeShow how the characteristics of your species

are related to the results of tests that you hadDiscuss any problems that occurred and give

possible causes for those problems

Conclusion: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.

References:Lab manualPersonal communicationsBergey’s Manual…Your textbookWebsites – use complete URLOther sourcesReferences 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 didDo 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 inkUse reasonable margins and fontPut your name somewhere on the reportNO cover or coversheetLength – long enough to get the job done

How to get started

Writing is hard!Start with what you know best – your

Materials and Methods sectionThen continue on with your Results sectionWrite your Discussion section nextThen finish with the rest of the sections

GradingGradesheet in D2L10 points for correctly identifying your two

speciesResults = 20 pointsDiscussion = 25 points (THE most important

section)Minimum score of 70% to finish the courseLate point deduction = -10 points per day

late

The End