2.2 Describe the tests and investigations that may be carried out upon the specimens

This guide will help you answer 2.2 Describe the tests and investigations that may be carried out upon the specimens.

Specimens are samples collected from an individual. They may include blood, urine, sputum (mucus from the lungs), faeces, wound swabs, or tissue. Teams working in health and social care often support people by collecting and sending these samples for testing. These tests help identify illness, infections, monitor health, and support diagnosis and treatment.

Health professionals rely on accurate tests to make decisions about care. Mistakes or delays can impact people’s well-being. That’s why understanding the different tests and their purposes is important.

Main Types of Specimens Collected

Different types of specimens are used for various tests. The main ones include:

• Blood
• Urine
• Sputum
• Stool (faeces)
• Saliva
• Wound swabs
• Tissue samples
• Cerebrospinal fluid (from around the brain and spinal cord)

Each specimen type can give different information about a person’s health.

Blood Tests

Blood is one of the most common specimens tested. Blood tests help check for diseases, organ function, nutrient levels, and infections.

Blood tests may include:

• Full blood count (FBC): Measures red cells, white cells, platelets. Helps detect anaemia, infection, or some cancers.
• Urea and electrolytes (U&E): Looks at kidney function and salt balance.
• Liver function tests (LFTs): Checks for liver disease or damage.
• Blood glucose: Monitors diabetes.
• Thyroid function tests: Checks if the thyroid gland works correctly.
• Blood cultures: Detects infection in the blood.
• Blood clotting tests (e.g., INR, APTT): Shows how well blood clots.

Blood samples may be taken by venepuncture (from a vein) or finger prick.

How Blood is Analysed

Once blood is collected:

1. It is labelled and sent to a laboratory.
2. Machines separate blood into different parts (plasma, cells) or examine cells under a microscope.
3. Chemical substances are measured using specialised tests.
4. Infections are identified by growing germs (culture) or testing for their DNA.
5. Results are reported to the health professional for interpretation.

Urine Tests

Urine specimens are easy to collect and test. Urine reflects what is happening in the body, such as kidney function or infection.

Common investigations include:

• Urine dipstick: A plastic strip dipped into urine checks for blood, protein, glucose, ketones (by-products from burning fat) and signs of infection.
• Urine microscopy: Looks at urine under a microscope for cells, crystals or bacteria.
• Urine culture: Grows bacteria from the sample to spot infection and test which antibiotics work.
• 24-hour urine collection: Gathers all urine over 24 hours to check kidney function or measure hormones.

How Urine is Analysed

The process involves:

1. Using sterile containers to avoid contamination.
2. Labelling accurately to avoid mix-ups.
3. Recording findings quickly, especially for dipstick testing.
4. Sending to the laboratory for further, more detailed analysis.

Sputum Tests

Sputum comes from deep in the lungs. It is collected if a chest infection or certain lung conditions are suspected.

Investigations on sputum include:

• Sputum microscopy: Microscope check for white cells, bacteria or fungi.
• Sputum culture: Bacteria are grown to spot infection and see which antibiotics could help.
• Acid-fast bacilli (AFB) test: Looks for tuberculosis (TB).
• PCR (Polymerase Chain Reaction): Tests for genetic material of viruses like COVID-19.

Collecting and Analysing Sputum

• Collect early morning samples, as these often contain the most bacteria.
• Ensure the person coughs deeply—saliva alone is not suitable.
• Once collected, the laboratory applies special stains to observe microbes under the microscope or uses machines to identify DNA or RNA.

Stool (Faeces) Tests

Stool samples are collected to investigate gut problems, infection, digestive issues, or bleeding.

Test types include:

• Stool culture: Checks for bacteria, viruses, or parasites.
• Faecal occult blood test (FOBT): Looks for hidden blood (may indicate cancer or ulcers).
• Ova, cysts and parasites (OCP): Examines stool for worm eggs or protozoa.
• Calprotectin test: Checks for inflammation in the bowel (Crohn’s or ulcerative colitis).

How Stool Samples are Tested

• Collection must use a sterile, leak-proof pot.
• Care is taken to avoid touching the sample with hands or mixing with urine or water.
• Quick delivery to the laboratory gives more accurate results.
• Staff may use stains, chemical reagents, or culture media to find the cause of illness.

Saliva Tests

Saliva testing can diagnose some infections, assess hormones, or detect drug use.

Common uses:

• Testing for viral illnesses (e.g., mumps, HIV, COVID-19).
• Hormone analysis, like measuring cortisol.
• Drug and alcohol screening.

Saliva samples are easy and non-invasive to collect, using a swab or by spitting into a tube. Lab machines then measure the substances of interest.

Wound Swabs

When a wound appears infected, a swab is used to collect pus or fluid. Swab specimens are tested to find which germs are present and check which antibiotics they may respond to.

Wound swabs are regularly tested by:

• Gram staining: Staining technique to classify bacteria under the microscope.
• Culture and sensitivity: Growing germs and checking which antibiotics kill them.

Results help doctors choose the right treatment. Swabs must be taken before antibiotics start, where possible, to avoid missing bacteria.

Tissue Samples (Biopsies)

Small pieces of body tissue are removed for testing if cancer or other diseases are suspected.

Types of tissue tests:

• Histology: Examining cells and tissue structures under a microscope.
• Immunohistochemistry: Using antibodies to find specific proteins linked to cancer or infection.
• Genetic testing: Looking for changes in the DNA of cells.

Biopsies can come from organs, skin, bone marrow, or lumps. Pathologists (specialist doctors) study the tissue and write a report for the medical team.

Cerebrospinal Fluid (CSF) Tests

CSF surrounds the brain and spinal cord. Rarely, samples are collected with a lumbar puncture to test for serious infections (like meningitis), bleeding, inflammation, or other brain problems.

Tests may include:

• Cell count: Checking for white or red blood cells.
• Culture: Looking for bacteria, viruses or fungi.
• Chemical analysis: Measuring protein and glucose levels.
• PCR tests: Hunting for genetic material of viruses or bacteria.

Test results support diagnosis and guide emergency treatments.

Special Laboratory Methods

Some tests need highly specialised methods. These can include:

• Polymerase Chain Reaction (PCR): Finds specific bits of DNA or RNA, useful for viruses and genetic conditions.
• Serology: Measures antibodies in blood, showing if someone has an infection or immunity.
• Flow cytometry: Examines blood or bone marrow cells for cancer (like leukaemia).
• Enzyme-linked immunosorbent assay (ELISA): Measures proteins, hormones, or antibodies.

These investigations provide answers that ordinary microscopy can’t. Samples may need special care, temperature control, or urgent transport.

Point of Care Testing

Some specimen tests are done near the person, not in the laboratory. This is called point of care (POC) testing. Examples include:

• Blood glucose meters for diabetes.
• Pregnancy test sticks.
• Urine dipsticks.

POC testing gives fast results. This means quicker decisions about care. Clear instructions and calibration keep results reliable.

Quality and Safety in Handling Specimens

Safe and accurate testing starts with the right collection, labelling, and transport of specimens. Risks include infection, misidentification, and contamination, which can lead to wrong results.

Good practice includes:

• Using correct containers and sterile equipment.
• Labelling every sample with the right patient details.
• Completing request forms with the right clinical information.
• Wearing gloves and washing hands before and after.
• Sending samples to the laboratory without delay.
• Recording the collection time and test requested.

Some specimens, such as blood or tissue, may need special handling for safety or to keep cells alive.

Infection Control in Specimen Handling

Preventing infection is a major concern. Handling any body fluids or tissue carries some risk.

Key practices:

• Wear gloves, aprons, and sometimes eye protection.
• Use sharps bins for needles.
• Clean and disinfect trays or surfaces after use.
• Dispose of waste safely.

Workers are responsible for their own and the person’s safety. They learn about infection risks during training and should always follow local procedures.

Understanding Test Results

Each test has reference values, showing what is normal. The health professional compares results to these values.

Abnormal results may point to:

• Infection
• Organ problems
• Bleeding
• Cancer
• Inflammation
• Drug levels that are too high or low

It is not the job of health or social care workers to interpret results. But understanding the purpose of tests helps provide better support, reassurance and communication to the person in their care.

Confidentiality with Specimens and Results

All specimen details and results are confidential. They count as sensitive information under the law. Sharing them inappropriately could break the rules and lead to disciplinary or even legal action.

Key points:

• Only the care team should see results.
• Results should be shared respectfully and privately.
• Paper or digital records must be kept secure.

When a person asks about their results, it is best to refer them to a qualified health professional for detailed discussion.

Communicating about Tests

Many people feel anxious about specimen tests. Workers should offer clear, calm explanations.

Techniques include:

• Telling the person what the test is for.
• Explaining what will happen during collection.
• Reassuring about safety and privacy.
• Listening to concerns and answering questions honestly.
• Referring any difficult queries to a nurse or doctor.

Clear communication strengthens trust and helps the overall care process.

Supporting People during Tests and Investigations

Health and social care workers play a part in preparing and supporting the person.

Support includes:

• Providing clear instructions about when and how to collect samples.
• Giving or organising information leaflets.
• Offering a private space for collection.
• Respecting cultural or religious attitudes about body fluids.
• Helping those with disabilities or communication needs.
• Watching for signs of distress and asking if the person needs help.

Some people might need extra support, such as reassurance, physical help, or an interpreter.

Responding to Results

Workers may be involved in following up results, as instructed by the care team. This could include organising further tests, passing on paperwork, or scheduling appointments.

If the specimen shows a serious or urgent issue, results are usually passed straight to a doctor for rapid action.

Record Keeping

Accurate record keeping is important throughout the testing process. Workers record:

• Time and date of collection.
• Type of sample.
• Tests requested.
• Any problems encountered.
• The person’s consent and understanding.

Good records keep care safe, legal, and well-coordinated.

Local Policies and National Guidelines

All organisations have rules about collecting and handling specimens. These protect everyone involved.

Guidelines come from national bodies, such as:

• The National Institute for Health and Care Excellence (NICE)
• Public Health England
• Care Quality Commission (CQC)

These set standards for infection control, consent, confidentiality, and safety.

Final Thoughts

Specimen tests and investigations cover a wide range of samples and techniques. Each test provides different types of information about a person’s health. Safe collection, handling, and communication help the care team diagnose illness, monitor treatment, and support the individual effectively. By understanding the processes and reasons for these tests, you can play a valuable part in the person’s care and well-being.