Gram Staining Protocol: Standard Operating Procedure (sop)

STANDARD OPERATING PROCEDURE (SOP)

Document ID: SOP-LAB-[]
Title: Gram Staining Protocol
Effective Date: []
Revision Number: [__________]
Department: [____________________]

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1. PURPOSE

The purpose of this Standard Operating Procedure (SOP) is to establish a standardized, repeatable process for the Gram staining of bacterial specimens to differentiate between Gram-positive and Gram-negative organisms, ensuring consistency and accuracy in diagnostic or research outcomes within [____________________].

2. SCOPE

This procedure applies to all laboratory personnel and technicians involved in the preparation and microscopic examination of microbial cultures utilizing the Gram stain technique at [____________________].

3. RESPONSIBILITIES

• Laboratory Manager: Responsible for final approval of this SOP and ensuring all equipment is calibrated.
• Laboratory Personnel: Responsible for adherence to this protocol, accurate documentation, and maintenance of a sterile environment.

4. MATERIALS AND REAGENTS

• Microscope slides ([__________] grade)
• Inoculating loop/needle
• Bunsen burner or incinerator
• Gram Staining Kit (containing):
  • Crystal Violet (Primary Stain)
  • Gram’s Iodine (Mordant)
  • 95% Ethyl Alcohol or Acetone (Decolorizer)
  • Safranin (Counterstain)
• Immersion oil
• Compound light microscope

5. PROCEDURAL STEPS

5.1 Preparation of Smear

1. Label the slide with the specimen ID: [____________________].
2. Aseptically transfer a small amount of the culture onto the slide.
3. Air dry the slide completely.
4. Heat-fix the slide by passing it through the flame [__________] times.

5.2 Staining Procedure

1. Primary Stain: Apply Crystal Violet for [__________] seconds. Rinse gently with distilled water.
2. Mordant: Apply Gram’s Iodine for [__________] seconds. Rinse gently with distilled water.
3. Decolorization: Apply 95% Ethyl Alcohol drop-wise for [__________] seconds until run-off is clear. Immediately rinse with distilled water to stop the process.
4. Counterstain: Apply Safranin for [__________] seconds. Rinse gently with distilled water.
5. Drying: Blot dry using bibulous paper. Do not rub.

6. QUALITY CONTROL

• Verify reagents are within the expiration date: [____________________].
• Positive control organism used: [____________________].
• Negative control organism used: [____________________].

7. RECORD KEEPING

All results must be logged in the Laboratory Information Management System (LIMS) or the physical logbook located at [____________________].

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8. AUTHORIZATION AND APPROVAL

Prepared By:

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Signature
[], []
Name & Title
Date: [__________]

Reviewed By (Quality Assurance):

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Signature
[], []
Name & Title
Date: [__________]

Approved By (Department Head):

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Signature
[], []
Name & Title
Date: [__________]

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Annual Review Record:
Date of Review: [] | Reviewer Initials: []
Date of Review: [] | Reviewer Initials: []