Test Catalog

Test Id : GRAM

Gram Stain, Varies

Useful For
Suggests clinical disorders or settings where the test may be helpful

Identifying microorganisms in normally sterile body fluids

 

Screening sputum specimens for acceptability for bacterial culture 

 

Guiding initial antimicrobial therapy

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Name
A short description of the method used to perform the test

Conventional Gram Stain Procedure

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Gram Stain

Aliases
Lists additional common names for a test, as an aid in searching

Gram Stain

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Specimen Type
Describes the specimen type validated for testing

Varies

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Sources: Closed/open abscess, lower respiratory, fluid, tissue, or swab

Supplies: Culturette (BBL Culture Swab) (T092)

Container/Tube: Sterile container or culture transport swab (Dacron or rayon swab with aluminum or plastic shaft with either Stuart or Amies liquid medium)

Specimen Volume: Entire collection

 

Acceptable:

Slides: Prepared microscope slide

Collection Container/Tube: Sterile container or culture transport swab

Submission Container/Tube: Slide container

Collection Instructions: Apply original sample to surface of standard microscope slide using appropriate application method (determined by consistency of specimen type) to assure adequate transfer of specimen onto slide. Allow specimen to dry and then heat-fix the slide. Place in slide container for transport.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Swab/Other Blood, stool, vaginal/cervical secretions, throat, or nasal specimen

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Varies Refrigerated (preferred) 24 hours
Ambient 24 hours

Useful For
Suggests clinical disorders or settings where the test may be helpful

Identifying microorganisms in normally sterile body fluids

 

Screening sputum specimens for acceptability for bacterial culture 

 

Guiding initial antimicrobial therapy

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

The Gram stain is a general stain used extensively in microbiology for the preliminary differentiation of microbiological organisms. The Gram stain is one of the simplest, least expensive, and most useful of the rapid methods used to identify and classify bacteria.

 

The Gram stain is used to provide preliminary information concerning the type of organisms present directly from clinical specimens or from growth on culture plates. This stain is used to identify the presence of microorganisms in normally sterile body fluids (cerebrospinal fluid, synovial fluid, pleural fluid, peritoneal fluid). It is also used to screen sputum specimens to establish acceptability for bacterial culture (<25 squamous epithelial cells per field is considered an acceptable specimen for culture) and may reveal the causative organism in bacterial pneumonia.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

No organisms seen or descriptive report of observations.

Interpretation
Provides information to assist in interpretation of the test results

During the staining process, the crystal violet and iodine form a complex within the heat fixed cell. In gram-negative organisms, this complex is readily washed out by the acetone-alcohol. They appear red because they retain only the safranin dye (counterstain). Gram-positive organisms retain the crystal violet-iodine complex after decolorization and remain purple.

 

Cells and Organisms will be reported according to the following tables: 

 

White Blood Cells

Epithelial Cells

 

Organisms

Low

Power Field

(LPF-10x)

Rare (R)

< or =1

Oil Immersion Field

(OIF-100x)

Rare (R)

<1

Few (F)

1-9

Few (F)

1-5

Moderate (O)

10-25

Moderate (O)

6-30

Many (M)

>25

Many (M)

>30

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Over-decolorization may result in the loss of the crystal violet iodine complex from gram-positive organisms and result in a misinterpretation.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

Atlas R, Snyder J: Reagents, stains, and media: bacteriology. In Manual of Clinical Microbiology. Vol 1. 12th edition, Edited by KC Carroll, MA Pfaller. Washington DC, ASM Press, 2019, pp 331-361

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Description
Describes how the test is performed and provides a method-specific reference

The specimen is applied directly to the slide or may be concentrated first by centrifugation or cytocentrifugation and then placed on the slide. The slide is stained with crystal violet, stained with Gram iodine solution, decolorized with acetone-alcohol, counterstained with safranin stain, and blotted dry. The slide is examined using the oil immersion objective on the microscope.(Chan WW: Gram Stain. In Clinical Microbiology Procedures Handbook. Vol 1. Fourth edition. Edited by AL Leber. Washington, DC, ASM Press, 2016. Section 3.2.1)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Sunday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

Same day/1 day

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

Gram stained slides are retained for 7 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

87205

LOINC® Information

Test Id Test Order Name Order LOINC Value
GRAM Gram Stain 664-3
Result Id Test Result Name Result LOINC Value
Result LOINC Value Tooltip
GRAM Gram Stain 664-3

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports