Microbiology 20: Grading Guidelines for Unknown Identification
(Laboratory Exercises 9-1, 9-2, or 9-3)
Los Angeles Mission College
Your written report should include the tear-out sheet from the lab manual as well as an
extra sheet(s) for the additional information below:
Item
Points Comments
Unknown Number
-7 Penalty if it is missing or incorrect
Gram Reaction
10 Verify with instructor in class
Morphology
5 Verify with instructor in class
Arrangement(s)
3 May have multiple arrangements
Sketch (or picture) of Gram
2 Show color, shape, arrangement, magnification
stain
Others staining results
5 Only necessary stains, capsule, endospore, acid
(sketch or picture)
fast etc.
Motility
5 Determine by hanging drop
Colony characteristics:
From streak plate, include picture or sketch
Diameter
1 In millimeters
Colony appearance
1 Round, irregular, etc.
Other characteristics
1 Color, margin, etc
Agar slant growth
1 Age, amount, pattern, color, etc.
Growth in broth
1 Age, amount, pellicle, flocculent, etc.
Tests to identify unknown
15 Perform necessary tests for identification; will
vary for each unknown.
Indicate results for each test performed.
Consult Bergey’s Identification Manual, flow
charts from lab manual, and/or tables provided.
Narrative
15 Describe the process you followed in at least 1
to 2 paragraphs, including any problems or
unexpected results encountered.
Comment on any other relevant information and
include any additional pictures if available.
Species name
5 Identification of correct species
TOTAL
70