Buccal Smear Test – Indications, Procedures, Results

Last updated: February 8, 2026Reviewed date: February 8, 2026Reading time: 8 min read
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A buccal smear test is also called the Sex chromatin test, a Buccal swab test is a test where cells are taken from the cheek and it is fast, non-invasive, relatively comfortable, and can yield larger sample sizes than other collection methods. Cells are collected...

For severe symptoms, danger signs, pregnancy, child illness, or sudden worsening, seek urgent medical care.

বাংলা রোগী নোট এখনো যোগ করা হয়নি। পোস্ট এডিটরে “RX Bangla Patient Mode” বক্স থেকে সহজ বাংলা সারাংশ যোগ করুন।

এই তথ্য শিক্ষা ও সচেতনতার জন্য। এটি ডাক্তারি পরীক্ষা, রোগ নির্ণয় বা প্রেসক্রিপশনের বিকল্প নয়।

Article Summary

A buccal smear test is also called the Sex chromatin test, a Buccal swab test is a test where cells are taken from the cheek and it is fast, non-invasive, relatively comfortable, and can yield larger sample sizes than other collection methods. Cells are collected by scraping the cheek with a cotton swab is the painless removal of a sample of cells from the inside...

Key Takeaways

  • This article explains How the Test is Performed in simple medical language.
  • This article explains How to Prepare for the Test in simple medical language.
  • This article explains How the Test will Feel in simple medical language.
  • This article explains Why the Test is Performed in simple medical language.
Educational health guideWritten for patient understanding and clinical awareness.
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Emergency safety firstUrgent warning signs are highlighted below.

Seek urgent medical care if you notice

These warning signs are general safety guidance. Local emergency numbers and clinical judgment should always come first.

  • Severe symptoms, breathing difficulty, fainting, confusion, or rapidly worsening illness.
  • New weakness, severe pain, high fever, or symptoms after a serious injury.
  • Any symptom that feels urgent, unusual, or unsafe for the patient.
1

Emergency now

Use emergency care for severe, sudden, rapidly worsening, or life-threatening symptoms.

2

See a doctor

Book a professional medical evaluation if symptoms persist, worsen, recur often, affect daily activities, or occur in a high-risk patient.

3

Learn safely

Use this article to understand possible causes, tests, treatment options, prevention, and questions to ask your clinician.

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Definition

A buccal smear test is also called the Sex chromatin test, a Buccal swab test is a test where cells are taken from the cheek and it is fast, non-invasive, relatively comfortable, and can yield larger sample sizes than other collection methods. Cells are collected by scraping the cheek with a cotton swab is the painless removal of a sample of cells from the inside of your mouth (cheek). The cells can be used for genetic testing, as well as evaluated for the presence of Barr bodies (a mass seen in a normal female sex chromosome) aneurism, microdeletion syndromes, and a variety of polymerase chains reaction-based molecular genetic tests. The buccal mucosa is the lining of the cheeks and the back of the lips, inside the mouth where they touch the teeth.

By far the most frequent buccal cell type in cheek swabs were the pink non-keratinous superficial squamous cells (mean 70.5% of epithelial cells in children and 73.9% in adults), followed by the orange keratinous superficial squamous cells (mean 27.6% of epithelial cells in children and 19.6% in adults) and the blue

How the Test is Performed

The health care provider will gently scrape the inside of the cheek with a small spatula to collect cells for testing. Sometimes, you can do this yourself.

How to Prepare for the Test

Rinse and wash the mouth as instructed. The way it works is that the swab collects sample cells from the inside of your cheek, which contain DNA information in the form of buccal epithelial cells. Buccal sample swabs are generally preferred by those looking for DNA testing because they’re much less invasive than a blood test

How the Test will Feel

You will feel a scraping sensation as cells are removed from the cheek.

Why the Test is Performed

This test is done to get cells for chromosome or DNA analysis, most often for genetic testing.

This test may also help establish sexual identity. When the test is used in this way, it’s called the sex chromatin test.

Risks

There are no risks.

FAQ

What cells are found in buccal smear?

  • By far the most frequent buccal cell type in cheek swabs were the pink non-keratinous superficial squamous cells (mean 70.5% of epithelial cells in children and 73.9% in adults), followed by the orange keratinous superficial squamous cells (mean 27.6% of epithelial cells in children and 19.6% in adults) and the blue.

Why is a buccal swab used to collect a DNA sample?

  • Many law enforcement facilities prefer buccal swabbing to other sample collection methods because it is fast, non-invasive, relatively comfortable, and can yield larger sample sizes than other collection methods.

What is the purpose of a buccal smear?

  • A buccal smear is a test where cells are taken from the cheek. Cells are collected by scraping the cheek with a cotton swab. The cells can be used for genetic testing, as well as evaluated for the presence of Barr bodies (a mass seen in a normal female sex chromosome).

What is a buccal swab and why is it important?

  • A buccal smear is a noninvasive, fast, and relatively inexpensive diagnostic method for collecting genetic material. It is used for sex determination as well as aneusomy, microdeletion syndromes, and a variety of polymerase chain reaction-based molecular genetic tests.

What is the buccal mucosa?

  • The buccal mucosa is the lining of the cheeks and the back of the lips, inside the mouth where they touch the teeth.

How much DNA is in a buccal swab?

  • When compared to other oral sampling methods, such as buccal swabs or mouthwash, a 2mL saliva sample collected with Oragene yields approximately 11% bacterial DNA, substantially lower than mouthwash at 66% and cytobrushes at over 88% bacterial DNA.

Why are cheek swabs used for DNA fingerprinting?

  • The way it works is that the swab collects sample cells from the inside of your cheek, which contain DNA information in the form of buccal epithelial cells. Buccal sample swabs are generally preferred by those looking for DNA testing because they’re much less invasive than a blood test.

Can a saliva DNA test be wrong?

  • Many people question the accuracy of a saliva swab because it isn’t invasive. However, you can have peace of mind knowing a mouth swab test is just as accurate as any other DNA test collection method. And, unlike the finger prick or blood test, it certainly doesn’t hurt at all.

When is the best time to do a saliva DNA test?

  • As long as you haven’t eaten, drank anything, or chewed gum within the last 30 minutes, you can take your DNA sample at any time. Most customers find it the easiest to collect their DNA sample first thing in the morning, before brushing their teeth, on the day of the sample pickup.

How long does it take for a buccal swab to come back?

  • The general detection window in oral fluids is 5 to 48 hours, but again, that window can be longer for people who use a substance often or for a long period of time.

Can you eat before the cheek swab?

  • In the morning before eating is ideal. Otherwise, wait for at least 30 minutes after eating for the food particles to clear out of the mouth.

How do you fail a saliva DNA test?

  • There are several points at which a saliva sample can fail to yield high-quality genetic data. Firstly, the saliva sample may have been compromised, either by the collection tube leaking in transit or by a failure of the preservative solution to mix with the saliva after collection.

What can be found in a buccal swab?

  • A buccal swab, also known as a buccal smear, is a way to collect DNA from the cells on the inside of a person’s cheek. Buccal swabs are a relatively non-invasive way to collect DNA samples for testing. Buccal means cheek or mouth.

What happens if you eat before the DNA test?

  • Avoid putting anything in your mouth for at least an hour prior to collecting cheek-cell samples. Foreign particles from food, liquids, toothpaste, and tobacco byproducts don’t alter the DNA but they can mask it. The consequence is that the sample becomes degraded and therefore unusable for paternity testing.

Can I drink water before the DNA test?

  • Do not eat, drink (even water), smoke, or chew gum 30 minutes prior to providing your sample! If we are unable to analyze your first sample, you will be provided with a free replacement kit!

What happens when a mouth swab turns blue?

  • There will be a change in color when a sufficient amount of data has been collected. Hence, if you’re wondering what it means when a mouth swab drug test turns blue, it means that enough saliva has been collected to provide an accurate test. This color change is beneficial for a collector’s awareness.

What does it mean when a mouth swab drug test turns blue?

  • Once the Oral-Eze sample adequacy window turns blue indicating that a sufficient sample has been collected, instruct the donors to simply place their thumb on the ridges of the collector handle and slide forward (not push down) to detach the pad into the collection tube.

How long does sperm DNA last in a woman?

  • We know that sperm cells are found in the female reproductive tract for seven days after ejaculation or longer.

What cells are found in buccal smear?

  • By far the most frequent buccal cell type in cheek swabs were the pink non-keratinous superficial squamous cells (mean 70.5% of epithelial cells in children and 73.9% in adults), followed by the orange keratinous superficial squamous cells (mean 27.6% of epithelial cells in children and 19.6% in adults) and the blue.

What is the purpose of a buccal smear?

  • A buccal smear is a test where cells are taken from the cheek. Cells are collected by scraping the cheek with a cotton swab. The cells can be used for genetic testing, as well as evaluated for the presence of Barr bodies (a mass seen in a normal female sex chromosome).

How much DNA is in a buccal swab?

System Specifications
Starting Material: Human buccal swabs
Elution Volume: 150 µl
DNA Yield: 1-3 ng/µl in 150 µl (Normalized Buccal Cell Kit) or up to 6µg (Buccal Cell Kit)
DNA Size: Varies (depends on the quality of starting material)

What are the symptoms of buccal mucosa?

Common Symptoms of Buccal Mucosa Cancer
  • white, red, or dark patches in the mouth.
  • lump inside cheek tissue.
  • mouth pain or numbness.
  • soreness or a feeling that something is caught in your throat.
  • difficulty moving your jaw.
  • severe ear pain.
  • hoarseness.
  • loose teeth or pain around your teeth.

How do you treat buccal mucosa?

  • How is buccal mucosa cancer treated? Early-stage cancer of the buccal mucosa is often treated with surgery. Advanced cancer cases may require a combination of surgery and chemotherapy.

What causes buccal mucosa?

  • The buccal mucosa is the lining of the cheeks and the back of the lips, inside where they touch the teeth. The development of cancer cells or tumors in this area leads to carcinoma buccal mucosa, which is a type of oral cancer. It generally starts in the squamous cells that are thin and flat, and line the lips and the mouth.

How is buccal smear done?

  • A buccal smear is a test where cells are taken from the cheek. Cells are collected by scraping the cheek with a cotton swab. The cells can be used for genetic testing, as well as evaluated for the presence of Barr bodies (a mass seen in a normal female sex chromosome).
Doctor visit helper

Prepare before seeing a doctor

A simple rural-patient checklist to help you explain symptoms clearly, ask better questions, and avoid unsafe self-treatment.

Safety note: This is not a prescription or diagnosis. For severe symptoms, pregnancy danger signs, children with serious illness, chest pain, breathing difficulty, stroke-like weakness, or major injury, seek urgent care.

Which doctor may help?

Start with a registered doctor or the nearest qualified health center.

What to tell the doctor

  • Write when the problem started and how it changed.
  • Bring old prescriptions, investigation reports, and current medicines.
  • Write allergies, pregnancy status, diabetes, kidney/liver disease, and major past illnesses.
  • Bring one family member if the patient is weak, elderly, confused, or a child.

Questions to ask

  • What is the most likely cause of my symptoms?
  • Which danger signs mean I should go to hospital quickly?
  • Which tests are necessary now, and which can wait?
  • How should I take medicines safely and what side effects should I watch for?
  • When should I come for follow-up?

Tests to discuss

  • Vital signs: temperature, pulse, blood pressure, oxygen saturation
  • Basic physical examination by a clinician
  • CBC, urine test, blood sugar, or imaging only when clinically needed

Avoid these mistakes

  • Do not use antibiotics, steroid tablets/injections, or strong painkillers without proper medical advice.
  • Do not hide pregnancy, kidney disease, ulcer, allergy, or blood thinner use.
  • Do not delay emergency care when danger signs are present.

Medicine safety and first-aid guide

This section is for patient education only. It does not replace a doctor, pharmacist, or emergency care.

Safe first steps

  • Rest, drink safe water, and observe symptoms carefully.
  • Keep a written note of symptoms, duration, temperature, medicines already taken, and allergy history.
  • Seek medical care quickly if symptoms are severe, worsening, or unusual for the patient.

OTC medicine safety

  • For mild pain or fever, ask a registered pharmacist or doctor before using common over-the-counter pain/fever medicines.
  • Do not combine multiple pain medicines without advice, especially if you have kidney disease, liver disease, stomach ulcer, asthma, pregnancy, or take blood thinners.
  • Do not give adult medicines to children unless a qualified clinician advises it.

Avoid these mistakes

  • Do not start antibiotics without a proper medical decision.
  • Do not use steroid tablets or injections casually for quick relief.
  • Do not delay emergency care because of home remedies.

Get urgent help if

  • Severe symptoms, confusion, fainting, breathing difficulty, chest pain, severe dehydration, or sudden weakness need urgent medical care.
Medicine names, dose, and timing must be decided by a qualified clinician or pharmacist after checking age, pregnancy, allergy, other diseases, and current medicines.

For rural patients and family caregivers

Patient health record and symptom diary

Write your symptoms, medicines already taken, test results, and questions before visiting a doctor. This note stays on your device unless you print or copy it.

Doctor to discuss: Doctor / qualified healthcare provider
Tests to discuss with doctor
  • Basic vital signs: temperature, pulse, blood pressure, oxygen level if needed
  • Relevant blood, urine, imaging, or specialist tests only after clinical assessment
Questions to ask
  • What is the most likely cause of my symptoms?
  • Which warning signs mean I should go to emergency care?
  • Which tests are really needed now?
  • Which medicines are safe for my age, pregnancy status, allergy, kidney/liver/stomach condition, and current medicines?

Emergency warning signs such as chest pain, severe breathing difficulty, sudden weakness, confusion, severe dehydration, major injury, or loss of bladder/bowel control need urgent medical care. Do not wait for online information.

Safe pathway to proper treatment

Care roadmap for: Buccal Smear Test – Indications, Procedures, Results

Use this simple roadmap to understand the next safe steps. It is educational and does not replace examination by a doctor.

Go to emergency care if you notice:
  • Severe or rapidly worsening symptoms
  • Breathing difficulty, chest pain, fainting, confusion, severe weakness, major injury, or severe dehydration
Doctor / service to discuss: Qualified healthcare provider; specialist depends on symptoms and examination.
  1. Step 1

    Check danger signs first

    If danger signs are present, seek emergency care and do not wait for online information.

  2. Step 2

    Record the symptom story

    Write when symptoms started, severity, medicines already taken, allergies, pregnancy status, and test results.

  3. Step 3

    Visit a qualified clinician

    A doctor, nurse, or qualified healthcare provider can examine you and decide which tests or treatment are needed.

  4. Step 4

    Do only useful tests

    Do tests after clinical assessment. Avoid unnecessary tests, random antibiotics, or repeated medicines without diagnosis.

  5. Step 5

    Follow up and return early if worse

    If symptoms worsen, new warning signs appear, or treatment is not helping, return for review quickly.

Rural patient practical tips
  • Take a written symptom diary and all previous prescriptions/test reports.
  • Do not hide medicines already taken, even herbal or over-the-counter medicines.
  • Ask which warning signs mean urgent referral to hospital.

This roadmap is for education. A real diagnosis and treatment plan requires history, examination, and clinical judgment.

RX Patient Help

Ask a health question safely

Write your symptom story. A health professional or site editor can review it before any answer is prepared. This box is not for emergency care.

Emergency first: Severe chest pain, breathing trouble, unconsciousness, stroke signs, severe injury, heavy bleeding, or rapidly worsening symptoms need urgent local medical care now.

Frequently Asked Questions

Is this article a replacement for a doctor?

No. It is educational content only. Patients should consult a qualified clinician for diagnosis and treatment.

When should I seek urgent care?

Seek urgent care for severe symptoms, rapidly worsening condition, breathing difficulty, severe pain, neurological changes, or any emergency warning sign.

References

Add references, clinical guidelines, textbooks, journal articles, or trusted medical sources here. You can edit this area from the RX Article Professional Blocks panel.

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