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Urethral discharge – Gram stain; Feces – Gram stain; Stool – Gram stain; Joint fluid – Gram stain; Pericardial fluid – Gram stain; Gram stain of urethral discharge; Gram stain of the cervix; Pleural fluid – Gram stain; Sputum – Gram stain; Skin ulcer. সহজ বাংলা: শরীরের অস্বাভাবিক দাগ, ক্ষত বা ফোলা অংশ।" data-rx-term="lesion" data-rx-definition="A lesion is an abnormal area of tissue such as a spot, wound, patch, lump, or ulcer. সহজ বাংলা: শরীরের অস্বাভাবিক দাগ, ক্ষত বা ফোলা অংশ।">lesion – Gram stain; Gram stain of skin lesion; Gram stain of tissue biopsy
A Gram stain is a test used to identify bacteria. It is one of the most common ways to quickly diagnose bacterial infection in the body.
How the Test is Performed
How the test is performed depends on what tissue or fluid from your body is being tested. The test may be quite simple, or you may need to prepare ahead of time.
- You may need to provide a sputum, urine, or stool sample.
- Your health care provider may use a needle to take fluid from your body to test. This could be from a joint, from the sac around your heart, or from the space around your lungs.
- Your provider may need to take a tissue sample, such as from your cervix or skin.
The sample is sent to a laboratory.
- A small amount is spread in a very thin layer on a glass slide. This is called a smear.
- A series of stains are added to the sample.
- A lab team member examines the stained smear under the microscope, looking for bacteria.
- The color, size, and shape of the cells help identify the specific type of bacteria.
How to Prepare for the Test
Your provider will tell you what to do to prepare for the test. For some types of tests, you will not need to do anything.
How the Test will Feel
How the test will feel depends on the method used to take a sample. You may not feel anything, or you may feel pressure and mild pain, such as during a biopsy. You may be given some form of pain medicine so you have little or no pain.
Why the Test is Performed
You may have this test to diagnose an infection caused by bacteria. It can also identify the type of bacteria causing the infection.
This test can help find the cause of various health problems, including:
- Intestinal infection or illness
- Sexually transmitted diseases (STDs)
- Unexplained swelling or joint pain
- Signs of a heart infection or fluid buildup in the thin sac that surrounds the heart (pericardium)
- Signs of infection of the space around the lungs (pleural space)
- Cough that will not go away, or if you are coughing up material with a foul odor or odd color
- Infected skin sore
A normal result means that no bacteria or only “friendly” bacteria were found. Some types of bacteria normally live in certain areas of the body, such as the intestines. Bacteria normally don’t live in other areas, such as the brain or spinal fluid.
Talk to your provider about the meaning of your specific test results.
What Abnormal Results Mean
Abnormal results may indicate an infection. You will need further tests, such as a culture, to find out more about the infection.
Risks
Your risks depend on the method used to remove tissue or fluid from your body. You may have no risk at all. Other risks are rare, but may include:
- Infection
- Bleeding
- Heart or lung puncture
- Collapsed lung
- Breathing problems
- Scarring
Endocervical gram stain
Gram stain of cervix
Endocervical Gram stain is a method to identify bacteria on tissue from the cervix using a special series of stains.
How the Test is Performed
This test requires a sample of tissue from the lining of the cervical canal (the opening to the uterus).
You lie on your back with your feet in stirrups. The health care provider will insert an instrument called a speculum into the vagina. This instrument is used during regular female pelvic exams. It opens the vagina to better view certain pelvic structures.
After the cervix is cleaned, a dry, sterile swab is inserted through the speculum to the cervical canal and gently turned. It may be left in place for a few seconds to absorb as many germs as possible.
The swab is removed and sent to a laboratory, where it will be smeared on a slide. A series of stains called a Gram stain is applied to the sample. A laboratory technician looks at the stained smear under the microscope for the presence of bacteria. The color, size, and shape of the cells help identify the type of bacteria.
How to Prepare for the Test
DO NOT douche for 24 hours before the procedure.
How the Test will Feel
You may feel minor discomfort during specimen collection. This procedure feels very much like a routine Pap smear.
Why the Test is Performed
This test is used to detect and identify abnormal bacteria in the cervix area. If you develop signs of an infection or think that you have a sexually transmitted disease (such as gonorrhea), this test can help confirm the diagnosis. It can also identify the germ that is causing the infection.
This test is rarely done because it has been replaced with more accurate ones.
Normal Results
A normal result means no abnormal bacteria are seen in the sample.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
- Bacterial vaginosis
- Chlamydia
- Gonorrhea
- Yeast infection
The test may also be performed for gonococcal pain, swelling, stiffness, or reduced movement. সহজ বাংলা: জয়েন্টের প্রদাহ।" data-rx-term="arthritis" data-rx-definition="Arthritis means joint inflammation causing pain, swelling, stiffness, or reduced movement. সহজ বাংলা: জয়েন্টের প্রদাহ।">arthritis , to determine the site of the initial infection.
Risks
There is virtually no risk.
Considerations
If you have gonorrhea or another sexually transmitted disease, it is very important that all of your sexual partners also receive treatment, even if they have no symptoms.
Joint fluid Gram stain
Gram stain of joint fluid
Joint fluid Gram stain is a diagnosis. সহজ বাংলা: রক্ত/প্রস্রাব/নমুনা পরীক্ষা।" data-rx-term="laboratory test" data-rx-definition="A laboratory test examines blood, urine, tissue, or other samples to help diagnosis. সহজ বাংলা: রক্ত/প্রস্রাব/নমুনা পরীক্ষা।">laboratory test to identify bacteria in a sample of joint fluid using a special series of stains (colors). The Gram stain method is one of the most commonly used methods to rapidly diagnose bacterial infections.
How the Test is Performed
A sample of joint fluid is needed.
The fluid sample is sent to a lab where a small drop is placed in a very thin layer onto a microscope slide. This is called a smear. Several different colored stains are applied to the sample. The laboratory personnel will look at the stained smear under a microscope to see if bacteria are present. The color, size, and shape of the cells help identify the bacteria.
How to Prepare for the Test
For information on how to prepare for the removal of joint fluid, see joint fluid aspiration .
How the Test will Feel
For information on how it will feel when the joint fluid is removed, see joint fluid aspiration .
Why the Test is Performed
The test is performed when there is unexplained swelling, joint pain , and infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।" data-rx-term="inflammation" data-rx-definition="Inflammation is the body’s response to injury, infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।">inflammation of a joint, or to check for suspected joint infection.
Normal Results
A normal result means no bacteria are present on the Gram stain.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
Abnormal results mean bacteria were seen on the Gram stain. This may be a sign of a joint infection, for example, gonococcal arthritis or arthritis due to Staphylococcus aureus.
Risks
There is no risk to the person associated with a Gram stain. For information regarding risks related to the removal of joint fluid, see joint fluid aspiration .
Pericardial fluid Gram stain
Gram stain of pericardial fluid
Pericardial fluid Gram stain is a method of staining a sample of fluid taken from the sac surrounding the heart to diagnose a bacterial infection. The Gram stain method is one of the most commonly used techniques for the rapid diagnosis of bacterial infections.
How the Test is Performed
A sample of fluid will be taken from the sac surrounding the heart. Before this is done, some people may have a cardiac monitor to check for heart disturbances. Patches called electrodes are put on the chest, similar to during an electrocardiogram ( ECG ). You will have a chest x-ray or ultrasound before the test.
The skin of the chest is cleaned with antibacterial soap. A trained physician, often a cardiologist, inserts a small needle into the chest between the ribs and into the thin sac that surrounds the heart (the pericardium). A small amount of fluid is taken out.
You may have an ECG and chest x-ray after the procedure. Sometimes the pericardial fluid is taken during open heart surgery.
A drop of the pericardial fluid is placed in a very thin layer on a microscope slide. This is called a smear. A series of special stains are applied to the sample. This is called a Gram stain. A laboratory specialist looks at the stained slide under the microscope, checking for bacteria.
The color, size, and shape of the cells help identify the bacteria.
How to Prepare for the Test
You will be asked not to eat or drink anything for several hours before the test. A chest x-ray or ultrasound may be done before the test to identify the area of fluid collection.
How the Test Will Feel
You will feel pressure and some pain as the needle is inserted into the chest and when the fluid is removed. Your doctor should be able to give you pain medicine so that the procedure does not hurt very much.
Why the Test is Performed
Your doctor may order this test if you have signs of a heart infection or a pericardial effusion (fluid buildup) with an unknown cause.
Normal Results
A normal result means no bacteria are seen in the stained fluid sample.
What Abnormal Results Mean
If bacteria are present, you may have an infection of the pericardium or heart. Blood tests and bacterial culture can help identify the specific organism causing the infection.
Risks
Complications are rare but may include:
- Heart or lung puncture
- Infection
Pleural fluid Gram stain
Gram stain of pleural fluid
The pleural fluid Gram stain is a test to diagnose bacterial infections in the lungs.
How the Test is Performed
Normally the lungs fill a person’s chest with air. If fluid builds up in the space outside the lungs but inside the chest, it can cause many problems. Removing the fluid can relieve a person’s breathing problems and help explain how the fluid built up there.
A sample of the fluid can be removed for testing. This process is called thoracentesis . One test that can be done on the pleural fluid involves placing the fluid onto a microscope slide and mixing it with a violet stain (called a Gram stain). A laboratory specialist uses a microscope to look for bacteria on the slide.
If bacteria are present, the color, number, and structure of the cells are used to identify the type of bacteria. This test will be done if there is concern that a person has an infection involving the lung or the space outside the lung but inside the chest (pleural space).
Why the Test is Performed
The test is performed when the health care provider suspects an infection of the pleural space, or when a chest x-ray reveals an abnormal collection of pleural fluid.
Normal Results
Normally, no bacteria are seen in the pleural fluid.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
You may have a bacterial infection of the lining of the lungs (pleura).
Gram stain of skin lesion
Skin lesion gram stain
A gram stain of a skin lesion is a laboratory test that uses special stains to detect and identify bacteria in a sample from a skin sore. The gram stain method is one of the most commonly used techniques to quickly diagnose bacterial infections.
How the Test is Performed
Your health care provider will remove a sample of tissue from the skin sore. For information on how this is done, see the article on skin lesion biopsy .
The sample is sent to a laboratory, where it is applied in a very thin layer to a glass slide. A series of different colored stains is applied to the sample. A laboratory team member examines the stained slide under a microscope, checking for bacteria. The color, size, and shape of the cells help identify the germ causing the infection.
How to Prepare for the Test
No preparation is needed for the laboratory test.
How the Test Will Feel
The laboratory test is painless. For information on what it feels like to have the skin sample removed, see: Skin lesion biopsy .
Why the Test is Performed
Your provider may order this test if you have signs of an infected skin sore. The test is done to determine which bacteria caused the infection.
Normal Results
The test is normal if no bacteria are found.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
An abnormal result means bacteria have been found in the skin lesion. Further tests are needed to confirm the results.
Risks
There are no risks related to the laboratory test. For information on risks related to removing a skin sample, see: Skin lesion biopsy .
Considerations
A skin or mucosal culture may be done along with this test. Other studies are often done on a skin sample to determine if cancer is present.
Viral skin lesions like herpes simplex are examined by other tests or a viral culture.
Sputum Gram stain
Gram stain of sputum
A sputum Gram stain is a laboratory test used to detect bacteria in a sputum sample. Sputum is the material that comes up from your air passages when you cough very deeply.
The Gram stain method is one of the most commonly used methods to rapidly detect a bacterial infection, including pneumonia.
How the Test is Performed
A sputum sample is needed. You will be asked to cough deeply and spit any material that comes up from your lung into a special container.
- If this does not work, you may receive a breathing treatment before the test to help you cough more deeply.
- If you have a dry cough or are unable to produce a sample, a bronchoscopy may be necessary.
The sample is sent to a lab. The lab team member places a very thin layer of the sample onto a glass slide. This is called a smear. Stains are placed on the sample. The lab team member looks at the stained slide under a microscope, checking for bacteria and white blood cells. The color, size, and shape of the cells help identify the bacteria.
How to Prepare for the Test
No preparation is usually needed, unless a bronchoscopy is necessary.
How the Test Will Feel
How the test will feel depends on the method used to produce the sample. More discomfort is associated with a bronchoscopy.
Why the Test is Performed
Your doctor may order this test if you have a persistent or prolonged cough, or if you are coughing up material that has a foul odor or unusual color. The test may also be done if you have other signs and symptoms of respiratory disease or infection.
Normal Results
A normal result means that few to no white blood cells and no bacteria were seen in the sample. The sputum is clear, thin, and odorless.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
An abnormal result means that bacteria is seen in the test sample. You may have a bacterial infection. A culture is needed to confirm the diagnosis.
RIsks
There are no risks associated with coughing up a sample. See the article on bronchoscopy for information regarding risks related to that procedure.
Considerations
The test may need to be repeated if the sample contains only saliva from the mouth.
Stool Gram stain
Gram stain of stool; Feces Gram stain
A stool Gram stain is a laboratory test that uses different stains to detect and identify bacteria in a stool sample.
The Gram stain method is sometimes used to quickly diagnose bacterial infections.
How the Test is Performed
You will need to collect a stool sample.
There are many ways to collect the sample.
- You can catch the stool on plastic wrap that is loosely placed over the toilet bowl and held in place by the toilet seat. Then you put the sample in a clean container.
- A test kit is available that supplies a special toilet tissue that you use to collect the sample. After collecting the sample, you put it in a container.
- Do not take stool samples from the water in the toilet bowl. Doing this can cause an inaccurate test result.
Do not mix urine, water, or toilet tissue with the sample.
For children wearing diapers:
- Line the diaper with plastic wrap.
- Position the plastic wrap so that it will prevent urine and stool from mixing. This will provide a better sample.
Your health care provider will give you instructions on when and how to return the sample.
The sample is sent to a laboratory. A small amount is spread in a very thin layer on a glass slide. This is called a smear. A series of special stains are added to the sample. The lab team member looks at the stained smear under the microscope to check for bacteria. The color, size, and shape of the cells help identify the specific bacteria.
How the Test will Feel
A lab smear is painless and does not directly involve the patient.
There is no discomfort when a stool sample is collected at home because it only involves normal bowel functions.
Why the Test is Performed
Your health care provider may order this test to help diagnose an intestinal infection or illness, sometimes involving diarrhea .
Normal Results
A normal result means only normal or “friendly” bacteria were seen on the stained slide. Everyone has friendly bacteria in their intestines.
Normal value ranges may vary slightly among different laboratories. Talk to your health care provider about the meaning of your specific test results.
What Abnormal Results Mean
An abnormal result means that an intestinal infection may be present. Stool cultures and other tests can also help diagnose the cause of the infection.
Risks
There are no risks.
Gram stain of tissue biopsy
Gram stain of tissue biopsy test involves using crystal violet stain to test a sample of tissue taken from a biopsy .
The Gram stain method can be used on almost any specimen. It is an excellent technique for making a general, basic identification of the type of bacteria in the sample.
How the Test is Performed
A sample, called a smear, from a tissue specimen is placed in a very thin layer on a microscope slide. The specimen is stained with crystal violet stain and goes through more processing before it is examined under the microscope for bacteria.
Characteristics of the bacteria, such as their color, shape, clustering (if any), and pattern of staining help determine the type of bacteria.
How to Prepare for the Test
If the biopsy is included as part of a surgical procedure, you will be asked not to eat or drink anything the night before surgery. If the biopsy is of a superficial (on the surface of the body) tissue, you may be asked not to eat or drink for several hours before the procedure.
How the Test Will Feel
How the test feels depends on the part of the body being biopsied. There are several different methods for taking tissue samples.
- A needle may be inserted through the skin to the tissue.
- A cut (incision) through the skin into the tissue may be made, and a small piece of the tissue removed.
- A biopsy may also be taken from inside the body using an instrument that helps the doctor see inside the body, such as an endoscope or cystoscope.
You may feel pressure and mild pain during a biopsy. Some form of pain relieving medicine (anesthetic) is usually given so you have little or no pain.
Why the Test is Performed
The test is performed when an infection of a body tissue is suspected.
Normal Results
Whether there are bacteria, and what type there are, depends on the tissue being biopsied. Some tissues in the body are sterile, such as the brain. Other tissues normally contain bacteria.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
Abnormal results usually mean there is an infection in the tissue. More tests, such as culturing the tissue that was removed, are often needed to identify the type of bacteria.
Risks
The only risks are from taking a tissue biopsy, and may include bleeding or infection.
Gram stain of urethral discharge
Urethral discharge Gram stain; Urethritis – Gram stain
A Gram stain of urethral discharge is a test used to identify bacteria in fluid from the tube that drains urine from the bladder (urethra).
How the Test is Performed
Fluid from the urethra is collected on a cotton swab. A sample from this swab is applied in a very thin layer to a microscope slide. A series of stains called a Gram stain is applied to the specimen.
The stained smear is then examined under the microscope for the presence of bacteria. The color, size, and shape of the cells help identify the type of bacteria causing the infection.
How to Prepare for the Test
This test is often performed in the health care provider’s office.
How the Test will Feel
You may feel pressure or burning when the cotton swab touches the urethra.
Why the Test is Performed
The test is performed when an abnormal urethral discharge is present. It may be performed if a sexually transmitted infection is suspected.
Normal Results
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.
What Abnormal Results Mean
Abnormal results may indicate gonorrhea or other infections.
Risks
There are no risks.
Considerations
A culture of the specimen ( urethral discharge culture ) should be performed in addition to the gram stain. More advanced tests (such as PCR tests) may also be done.
