Gram Stain

Gram Stain test is used as a screening test to detect, the presence of some pathogens like bacteria, fungi and other harmful microbes present in certain (suspected) infected regions within the body. Thus this Gram Stain is used to identify the type of microbe (especially to differentiate bacteria – gram-positive or gram-negative or acid-fast bacteria etc) present in the pathological body fluids and/or in the suspected infected region (eg. in non-healing wound etc) and this (microscopic investigating analysis) test results help in the initiating the most appropriate antibiotic treatment for that causative micro-organism.
Test Code: 1229
₹ 150.00

Gram Stain:

Why Gram Stain Test?


A Blood test is a laboratory analysis done on a blood sample specimen to determine the biochemistry of an individual’s physiological condition (mostly done in pathological states). Multiple tests for specific blood components are performed through various biochemical tests, which are called metabolic panel tests or comprehensive metabolic panel tests. Blood tests also include the screening for the diagnosis of harmful microbial pathogens. Gram stain is performed to identify the nature of microorganisms. This test primarily aims at analyzing, for any incidence caused by some infectious microbes inside the body (like aerobic and/or anaerobic microbes, mycobacterium, fungi, virus-like microorganisms present in the blood sample specimen) that manifests with clinical signs and symptoms of an infection. Hence, the suspected blood sample specimen (mainly in systemic infection and cases like sepsis) of the patient is smeared on its suitable culture medium to check for the growth of microorganisms. After the culture growth from the patient’s blood sample specimen, the slide preparation is done along with staining techniques and the presence of microorganism is viewed under a microscope to investigate and determine the nature of the pathogen present on it. Gram Stain Test: This test checks for the presence of harmful pathogenic microbes in suspected infection, for example in the throat, lungs, skin wounds, genitals etc and moreover in body fluids such as blood, urine etc. The two main categories of bacterial infections are gram-positive and gram-negative. This screening for diagnosis is done by the differentiation made, based on how the bacteria react to the gram stain. A gram stain is coloured purple and if the bacteria remain in purple colour it is gram-positive bacteria and incases the bacteria turns red or pink they are gram-negative bacteria. Examples of gram-positive bacteria include nosocomial infection caused by Methicillin-Resistant Streptococcusaureus (MRSA), Strep infections, toxic shock etc. Examples of gram-negative infections include Salmonella, pneumonia, gonorrhea, Urinary Tract Infections - UTIs etc. The significance of differentiating the nature of bacteria as gram-positive or gram-negative helps the physician to begin the most effective antibiotic therapy for treating it. If the test result shows the presence of more than (≥15) colonies along with the same organism isolated from peripheral blood along with clinical signs and symptoms, then the case is said to be an infected positive case. Other gram stain tests include the Acid Fast Test (eg. For mycobacterium causing TB etc). Clinical manifestations include chills, fever, fatigue, nausea, confusion, increased heart rate, nasal flare due to increased breathing -which may or may not be associated with shortness of breath on physical exertion, inflammation (presenting with cardinal signs of inflammation like – rubor, tumour, calor, dolor and loss of function), blood clots, drop in blood pressure, organ failure, elevated WBCs etc. Once tested positive, then the additional supportive tests are ordered for - Evidence-Based Therapy (EBT) such as CBC, test for the presence of bacterial toxins (release of toxic by-products) eg staphylococcal infection, in case of foodborne-illness/food poison (or their toxins), different sample specimen collected for tests eg. blood, stool, urine culture, sputum test, CSF sampling, ascetic fluid, pleural fluid, pericardial fluid, synovial fluid, complement test (to check for increased levels of C3) etc. Moreover, sensitivity tests (also known as susceptibility testing) are also performed in addition, to appropriate antibiotic treatment & for better prognosis eg. MRSAMethicillin-Resistant Staphylococcus aureus, VMSAVancomycin-Resistant Staphylococcus aureus etc. 

General Instructions:

Sample Requirement: Specimen –eg. Pus, Body Fluid and Sputum (As guided by the physician). Test Preparation: None.

NOTE - Sample for specimen collections may vary based on the patient’s condition/cases according to the patient’s presenting complaints/signs or symptoms:

SPECIMEN REQUIREMENT (Special or Rare Cases) - As instructed and guided by Physician / Clinician / Pathologist / as per Laboratory’s requirements, according to procedures and protocols.

This Multi-Specialty Clinical Referral Laboratory RT DIAGNOSTICS provides precise and accurate tests with an extensive range of testing services to the medical centres to help in the diagnosis and identification of pathology in the test specimens for infectious diseases and also to evaluate the function of organ systems of the patient. It prevents further complications and helps to stabilize and restore health to near normalcy at the earliest without delay.