Test Name: Gram


Methodology: Special Stains


Test Description

Gram Stain Kit is used to identify two distinct groups of microorganisms in tissue sections on Artisan™ Link and Artisan™ Link Pro Staining Systems. Those that retain primary dye (Crystal Violet) are called Gram-positive. Those that lose the primary dye during decolorization are called Gram-negative. Mechanisms of Gram-positive organisms retaining the primary stain and Gram-negative organisms losing the primary stain are the result of the chemistry and structure of the organism’s cell walls. The tissue elements are stained as follow: Gram-positive organisms: blue, Gram-negative organisms: red and background: varying shades of blue/green.


Specimen Requirements

A formalin-fixed, paraffin-embedded (FFPE) tissue block is preferred specimen type or one (1) unbaked, unstained slide cut at 4-5 microns for H&E staining (required) and two to three (2-3) positively charged unstained slides cut at 3-4 microns for each test/antibody ordered.


Storage and Transport

Use cold pack during transport of paraffin blocks and unstained slides. Cold pack should not be placed in direct contact with the specimen during shipping


Specimen Rejection Criteria

Click here to reference the specimen rejection criteria.


Turn Around Time (TAT): 2-3 Days


CPT Codes*: 88312


*The CPT codes provided with our Test Descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.