Reading and Reporting Gram Stained Direct Smears (Online Course)

(based on 1723 customer ratings)

Authors: Betty Smith, MT (ASCP), Jaimy Hill, MT (ASCP)

Has your laboratory ever had difficulty correctly reporting out cerebrospinal and joint fluid gram stains during off hours? This course helps provide training for technologists who must read gram stain but do not work primarily in the microbiology laboratory. Great for cross-training and for clinical laboratory science students as well.

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Continuing Education Credits

  • P.A.C.E.® Contact Hours: 1.5 hour(s)
  • Florida Board of Clinical Laboratory Science CE - General (Microbiology/Mycology/Parasitology): 1.5 hour(s)


  • Define a direct smear.
  • Describe several ways that Gram stained direct smears are clinically useful.
  • Discuss examination of direct smears with respect to: control smears, macroscopic appearance, and characteristics of appropriate microscopic fields.
  • Discuss the identification of common nonbacterial elements with respect to: purpose, size, shape, differentiating characteristics, and Gram stain reaction.
  • Identify the following types of bacteria found in Gram stained direct smears: gram-positive cocci, gram-negative cocci, gram-positive bacilli, gram-negative bacilli, gram negative diplococci.
  • Discuss the procedure for reading Gram stained direct smears with respect to: principle, procedure, and sources of error.

Customer Ratings

(based on 1723 customer ratings)

Course Outline

  • Purpose of the Gram Stained Direct Smear
      • What is the Value of a Direct Smear?
      • Determine the Quality of a Sputum Specimen
      • Determine the Quality of a Urine Specimen Submitted for Culture
      • Provide the Clinician With Same-Day Information Regarding Possible Pathogens
      • Cerebrospinal Fluid and Specimens Collected from Other Sterile Sites
      • Correlate Direct Smear Results With Culture Results
      • Information from Gram stained direct smears may help the physician make a preliminary diagnosis when the Gram stain information is comb...
      • A large number of which of these types of cells would indicate that a sputum specimen is sub-optimal and should not be used for culture?
  • Reading and Reporting Direct Smears
      • Gram Stain Principle
      • Quality Control Smears
      • Macroscopic Evaluation of the Smear
      • Thick Smears
      • Thin Smears
      • Properly Decolorized Smears
      • Under-decolorized or Over-decolorized Smears
      • Reporting Microscopic Findings
      • Contaminated Gram Stain Solution
      • Summary of Gram Stain Reading and Reporting Procedure
      • What color is the background material in a Gram-stained smear that has been adequately decolorized?
      • What is the MINIMUM number of fields that should be examined before reporting a Gram-stained direct smear?
      • If a smear is over-decolorized, it can be salvaged by repeating the Gram staining procedure.
      • What is the purpose of the iodine that is used in the Gram stain procedure?
      • Which of the following statements is true regarding the Gram-stained smear that is represented by this image?
  • Bacteria in Direct Smears
      • Gram-positive Cocci
      • Gram-positive Diplococci
      • Gram-negative Cocci
      • Intracellular Bacteria
      • Gram-negative Diplococci
      • Special Considerations for Genital Smears
      • Gram-positive Bacilli
      • Gram-negative Bacilli
      • Significance of Specific Findings
      • The bacteria in this slide are gram-negative cocci.
      • What are the structures indicated by the arrows in this field from a Gram-stained smear?
      • The presence of intracellular gram-negative diplococci on a smear made from a purulent urethral discharge from a male can be confirmatory of the diagn...
  • Nonbacterial Cells in Direct Smears
      • Size and Appearance of Nonbacterial Cellular Elements on Gram Stained Smears
      • Match the Gram stain reaction for each of the following nonbacterial elements.
      • Which of the following cells are about the same size as red blood cells?
      • What nonbacterial structures are present in this microscopic field of a Gram-stained smear? (Choose ALL that apply)
      • This Gram stain was prepared from a sputum specimen and is viewed under oil immersion (1000X). What is the structure that is indicated by the arrow?
  • References
      • References

Additional Information

This course describes the morphology and Gram stain reactions of bacteria and nonbacterial elements found in Gram stained smears of clinical material.
Level of Instruction: Basic

Intended Audience: This course is suitable for basic clinical microbiology courses at the post-secondary level. It can also be used as review material for clinical laboratory practitioners, medical students, and pathology residents.

Prerequisites: Skill in the use of the microscope, aseptic techniques, experience preparing and gram staining smears, and experience reading smears from cultures.

Author Credentials: This course was developed by Betty Smith MT (ASCP) and Jaimy Hill MT (ASCP), and was updated by Education Materials for Health Professionals, Inc., under the supervision of Marjorie Spahn MT(ASCP).It wa reviewed and adapted for online use by Paul Fekete, M.D. fellow C.A.P.

Copyright: Copyright EMHP Inc.,Dayton OH. Licensed to MediaLab Inc., Dacula, GA. Web-based version produced solely by MediaLab Inc.




appropriate reading field for gram stain



Gram positive bacilli