Key Takeaways
- CLIA (Clinical Laboratory Improvement Amendments of 1988) regulates all laboratory testing on human specimens in the U.S.
- CLIA classifies tests into three categories: waived, moderate complexity, and high complexity
- CLIA-waived tests can be performed by medical assistants and include glucose meters, urine dipsticks, rapid strep, pregnancy tests, and hemoglobin A1c
- Quality control (QC) procedures include running control samples, calibrating equipment, and documenting results to ensure accuracy
- Urinalysis has three components: physical (color, clarity, specific gravity), chemical (dipstick), and microscopic (sediment examination)
- Normal urine is pale yellow to amber, clear, slightly acidic (pH 4.5-8.0), with a specific gravity of 1.005-1.030
- Hematology tests include CBC (complete blood count), hemoglobin, hematocrit, WBC differential, and platelet count
- Chemistry panels include BMP (basic metabolic panel) and CMP (comprehensive metabolic panel) testing electrolytes, glucose, kidney function, and liver function
- Proper specimen labeling requires patient name, date of birth, date/time of collection, collector initials, and specimen type
Last updated: February 2026
Laboratory Procedures & CLIA Regulations
Medical assistants perform laboratory tests and collect specimens as part of daily clinical practice. Understanding CLIA regulations, quality control, and common laboratory procedures is essential for the RMA exam.
CLIA (Clinical Laboratory Improvement Amendments of 1988)
CLIA regulates all laboratory testing performed on human specimens in the United States to ensure quality and accuracy.
CLIA Test Classifications
| Category | Complexity | Who Can Perform | Examples |
|---|---|---|---|
| Waived | Simplest, lowest risk of error | Medical assistants with CLIA-waived certificate | Glucose meters, urine dipstick, rapid strep, pregnancy test, hemoccult, rapid flu, HbA1c |
| Moderate complexity | Intermediate | Trained lab personnel with moderate complexity certificate | CBC (automated), urinalysis (microscopic), Gram stain, chemistry analyzers |
| High complexity | Most complex | Qualified lab professionals only | Cytology (Pap smears), complex immunoassays, molecular diagnostics |
Quality Control (QC) Requirements
| QC Element | Purpose | Frequency |
|---|---|---|
| Control samples | Verify test accuracy (known positive and negative) | Per manufacturer instructions; typically each day of testing |
| Calibration | Ensure equipment measures accurately | Per manufacturer schedule |
| Proficiency testing | External validation of lab accuracy | Periodically (for non-waived labs) |
| Documentation | Record all QC results, corrective actions | Every time QC is performed |
| Temperature logs | Verify storage conditions for reagents/specimens | Daily for refrigerators/freezers |
Urinalysis
Urinalysis is one of the most commonly performed tests in a medical office and has three components:
Physical Examination
| Property | Normal | Abnormal Findings |
|---|---|---|
| Color | Pale yellow to amber | Red/brown (blood), orange (bilirubin, medications), cloudy (infection) |
| Clarity/turbidity | Clear to slightly hazy | Cloudy or turbid (bacteria, WBCs, crystals) |
| Specific gravity | 1.005 - 1.030 | High (dehydration, diabetes), Low (overhydration, kidney disease) |
| Odor | Slightly aromatic | Foul/ammonia (infection, old specimen), fruity (ketones/diabetes) |
Chemical Examination (Dipstick)
| Parameter | Normal | Clinical Significance |
|---|---|---|
| pH | 4.5 - 8.0 | Acidic: diet, medications; Alkaline: UTI, old specimen |
| Protein | Negative | Positive: kidney disease, preeclampsia, UTI |
| Glucose | Negative | Positive: diabetes mellitus, gestational diabetes |
| Ketones | Negative | Positive: DKA, starvation, low-carb diet |
| Blood | Negative | Positive: UTI, kidney stones, menstruation |
| Bilirubin | Negative | Positive: liver disease, bile duct obstruction |
| Urobilinogen | Normal (0.1-1.0 EU/dL) | Elevated: liver disease, hemolytic disorders |
| Nitrites | Negative | Positive: bacterial UTI (gram-negative organisms) |
| Leukocyte esterase | Negative | Positive: WBCs present, indicating infection |
| Specific gravity | 1.005 - 1.030 | High: concentrated; Low: dilute |
Microscopic Examination
| Element | Normal (per HPF) | Clinical Significance |
|---|---|---|
| RBCs | 0-2 | Elevated: stones, trauma, infection, cancer |
| WBCs | 0-5 | Elevated: UTI, inflammation |
| Bacteria | Few or none | Many: UTI |
| Epithelial cells | Few squamous | Many: contamination or infection |
| Casts | Occasional hyaline | Cellular casts: kidney disease |
| Crystals | Few | May indicate stones or metabolic conditions |
Common Laboratory Tests
Hematology
| Test | Normal Range | Clinical Use |
|---|---|---|
| WBC (white blood cells) | 4,500 - 11,000/mcL | Elevated: infection, inflammation; Low: immunosuppression |
| RBC (red blood cells) | M: 4.5-5.5; F: 4.0-5.0 million/mcL | Elevated: polycythemia; Low: anemia |
| Hemoglobin (Hgb) | M: 13.5-17.5; F: 12.0-16.0 g/dL | Oxygen-carrying capacity; low in anemia |
| Hematocrit (Hct) | M: 38-50%; F: 36-44% | % of blood volume that is RBCs |
| Platelet count | 150,000 - 400,000/mcL | Low: bleeding risk; High: clotting risk |
| ESR (sed rate) | M: 0-15; F: 0-20 mm/hr | Non-specific inflammation marker |
| PT/INR | PT: 11-13.5 sec; INR: 0.8-1.1 | Monitors warfarin therapy; INR target 2.0-3.0 |
Chemistry / Metabolic Panels
| Test | Normal Range | Clinical Use |
|---|---|---|
| Glucose (fasting) | 70-100 mg/dL | Diabetes screening/monitoring |
| BUN | 7-20 mg/dL | Kidney function |
| Creatinine | 0.7-1.3 mg/dL | Kidney function (more specific than BUN) |
| Sodium (Na+) | 136-145 mEq/L | Fluid balance |
| Potassium (K+) | 3.5-5.0 mEq/L | Critical for cardiac function |
| Chloride (Cl-) | 98-106 mEq/L | Acid-base balance |
| CO2 (bicarbonate) | 23-29 mEq/L | Acid-base balance |
| Calcium (Ca2+) | 8.5-10.5 mg/dL | Bone health, parathyroid function |
| Total cholesterol | < 200 mg/dL | Cardiovascular risk |
| LDL cholesterol | < 100 mg/dL | "Bad" cholesterol |
| HDL cholesterol | > 40 mg/dL (M), > 50 (F) | "Good" cholesterol |
| Triglycerides | < 150 mg/dL | Cardiovascular/metabolic risk |
| HbA1c | < 5.7% | 2-3 month average blood glucose |
Specimen Collection and Handling
| Principle | Details |
|---|---|
| Patient identification | Verify identity using two identifiers (name + DOB) before collection |
| Labeling | Label at the time of collection with: patient name, DOB, date/time, collector initials, specimen type |
| Chain of custody | Required for drug testing, legal specimens; documents handling from collection to analysis |
| Transport | Follow specific requirements (temperature, timing, container type) |
| Fasting specimens | Patient should fast 8-12 hours (water allowed); common for glucose, lipid panels |
Test Your Knowledge
Which of the following is a CLIA-waived test that a medical assistant can perform?
A
B
C
D
Test Your Knowledge
A urine sample that tests positive for both leukocyte esterase and nitrites most likely indicates:
A
B
C
D
Test Your Knowledge
The normal fasting blood glucose range is:
A
B
C
D
Test Your Knowledge
Before collecting a blood specimen, the medical assistant must verify the patient's identity using:
A
B
C
D
Test Your KnowledgeFill in the Blank
CLIA stands for Clinical Laboratory Improvement Amendments of ___.
Type your answer below
Test Your KnowledgeMatching
Match each urine dipstick finding with its most likely clinical significance.
Match each item on the left with the correct item on the right
1
Glucose positive
2
Ketones positive
3
Bilirubin positive
4
Nitrites positive
5
Protein positive