Medical Assistant Certification (CMA / RMA) Laboratory and Diagnostic Testing Syllabus

What is hemoconcentration and what causes it?

An increased concentration of cells and large molecules in blood; caused by prolonged tourniquet application or excessive fist pumping.

If blood stops flowing into the tube during a draw ('missed vein'), what adjustments can you try?

Slightly advance or withdraw the needle, rotate the bevel, try another tube, or check that the tube vacuum is intact; if unsuccessful, discontinue and select another site.

What is venous reflux and how is it prevented?

Backflow of tube additive into the patient's vein; prevented by keeping the patient's arm downward and the tube below the puncture site so it fills from the bottom up.

What is the minimum information that must appear on a specimen label?

Patient full name, unique identifier (DOB or MRN), date and time of collection, and the collector's initials/ID.

When must a specimen be labeled?

Immediately at the patient's side (bedside), in the presence of the patient, before leaving the patient.

What is chain of custody and when is it required?

A documented, unbroken record of specimen handling, transfer, and storage; required for legal/forensic specimens such as drug screens and blood alcohol for legal purposes.

What information does a chain-of-custody form track?

Specimen identity, every person who handled it, the date/time of each transfer, and tamper-evident seal integrity — ensuring the sample is traceable and unaltered for legal proceedings.

What is the purpose of centrifuging a blood specimen?

To separate blood into components by density — cells settle to the bottom and plasma/serum rises to the top — for testing the liquid fraction.

What is the difference between serum and plasma?

Plasma comes from anticoagulated blood and contains fibrinogen/clotting factors; serum comes from clotted blood (no anticoagulant) and lacks fibrinogen.

How long must a serum (red/SST) tube clot before centrifugation, and how long before serum should be separated from cells?

Allow about 30 minutes for full clotting; serum/plasma should generally be separated from cells within 2 hours of collection.

What does a gel separator (in an SST/PST tube) do during centrifugation?

The thixotropic gel moves to form a barrier between the cells and the serum/plasma, preventing contamination of the liquid fraction by cellular contents.

Why must centrifuge tubes be balanced before spinning?

Unbalanced loads cause vibration that can break tubes, damage the centrifuge, and cause hemolysis; place tubes of equal weight opposite each other.

What is aliquoting?

Dividing a single specimen into multiple smaller portions (aliquots), each transferred to a separate labeled tube for different tests or storage.

What are the three general temperature categories for specimen storage and their typical ranges?

Room temperature (~15–30 C / ambient), refrigerated (2–8 C), and frozen (-20 C or colder).

Which specimens are typically protected from light, and give an example analyte?

Light-sensitive specimens are wrapped in foil/amber containers; example analyte is bilirubin (also vitamin B12, folate, carotene).

What specimen handling is required for a cold agglutinin or cryoglobulin sample?

It must be kept warm at 37 C (body temperature) from collection through processing to prevent premature clumping/precipitation.

What is the preferred urine specimen for a routine urinalysis and culture?

A clean-catch midstream specimen, ideally the first morning void because it is most concentrated.

Describe the clean-catch midstream collection technique.

Cleanse the genital area front to back with antiseptic wipes, begin voiding into the toilet, then collect the midstream portion in a sterile container without touching the inside.

What is a 24-hour urine collection and how is it started?

A timed collection of all urine over 24 hours to measure analyte excretion; the patient discards the first morning void, notes the time, then collects all urine including the final void at the same time next day.

What patient instruction is essential for a fecal occult blood test (gFOBT) to avoid false positives?

Avoid red meat, certain raw vegetables (with peroxidase), vitamin C, NSAIDs/aspirin for several days before collection per kit instructions.

What are the three components of a complete urinalysis?

Physical (color, clarity, specific gravity), chemical (reagent dipstick), and microscopic examination of the sediment.

What does specific gravity in urinalysis measure, and what is the normal range?

The concentration (density) of urine relative to water; normal range is roughly 1.005–1.030.

On a urine reagent dipstick, what does a positive nitrite result suggest?

Presence of bacteria that convert nitrate to nitrite, suggesting a urinary tract infection (commonly gram-negative bacteria like E. coli).

What does a positive leukocyte esterase on a urine dipstick indicate?

The presence of white blood cells, suggesting infection or inflammation of the urinary tract.

What does glucose in the urine (glucosuria) typically indicate?

Blood glucose exceeding the renal threshold (~180 mg/dL), commonly seen in uncontrolled diabetes mellitus.

What does HbA1c (glycated hemoglobin) measure and over what time period?

The average blood glucose over the previous ~2–3 months, reflecting the lifespan of red blood cells.

What HbA1c value is diagnostic of diabetes, and what range indicates prediabetes?

HbA1c of 6.5% or higher diagnoses diabetes; 5.7%–6.4% indicates prediabetes (normal is below 5.7%).

What is the principle of a rapid strep test, and what should a negative result prompt?

It detects Group A Streptococcus antigen from a throat swab; because of limited sensitivity, a negative rapid test is often confirmed with a throat culture.

What type of test is a rapid mononucleosis test, and what does it detect?

A qualitative immunoassay that detects heterophile antibodies produced in response to Epstein-Barr virus infection.

What hormone do urine and serum pregnancy tests detect?

Human chorionic gonadotropin (hCG), produced by the developing placenta.

Why is a quality control (QC) sample run on point-of-care and lab instruments?

To verify that the test system, reagents, and operator are producing accurate, reliable results before patient samples are tested.

What is the difference between an internal (positive/procedural) control and an external control on a test device?

An internal/built-in control verifies the test ran correctly (e.g., the control line on a pregnancy test); an external control is a separate known-value sample used to validate the kit/lot and instrument.

Why must you check reagent expiration dates and lot numbers before testing?

Expired or improperly stored reagents can deteriorate and yield inaccurate results; documenting lot numbers allows traceability if a problem occurs.

What does an electrocardiogram (ECG/EKG) record?

The electrical activity of the heart over time, detected through electrodes placed on the skin.

How many electrodes and how many leads are used in a standard 12-lead ECG?

10 electrodes (6 chest/precordial + 4 limb) produce 12 leads (views) of the heart's electrical activity.

Where is the V1 chest electrode placed on a 12-lead ECG?

In the 4th intercostal space at the right sternal border.

Where is the V2 chest lead placed?

In the 4th intercostal space at the left sternal border.

Where are leads V4, V5, and V6 placed on the chest?

V4 at the 5th intercostal space, midclavicular line; V5 at the anterior axillary line level with V4; V6 at the midaxillary line level with V4.

What do the P wave, QRS complex, and T wave represent on an ECG?

P wave = atrial depolarization; QRS complex = ventricular depolarization; T wave = ventricular repolarization.

What is the standard paper speed and calibration for a routine ECG?

Paper speed of 25 mm/second and standard calibration of 10 mm = 1 millivolt.

What is an artifact on an ECG and name a common cause?

An abnormal signal not produced by the heart; common causes include patient movement/muscle tremor (somatic), AC electrical interference (60-cycle), wandering baseline, or loose electrodes.

How can 60-cycle (AC) interference on an ECG be reduced?

Move electrical cords/devices away, ensure proper grounding, check that lead wires aren't crossed, and verify good electrode contact.

What is a Holter monitor and how long is it typically worn?

A portable continuous ECG recorder worn for 24–48 hours to detect intermittent arrhythmias during normal daily activity.

What is the patient instructed to do while wearing a Holter monitor?

Keep a diary/log of activities and symptoms with times, maintain normal activity, and avoid getting the device wet (no bathing/swimming).

What is the purpose of a cardiac (exercise) stress test?

To evaluate the heart's response to exertion, typically using a treadmill or bike with continuous ECG and blood pressure monitoring to detect ischemia or arrhythmias.

What is a pharmacologic stress test and when is it used?

A test using medication (e.g., adenosine, dobutamine) to simulate exercise stress on the heart; used for patients unable to exercise physically.

What does spirometry measure?

Lung function — the volume and speed (flow) of air a patient can inhale and exhale.

What does FVC stand for in pulmonary function testing?

Forced vital capacity — the total amount of air forcefully exhaled after a maximal inhalation.

What does FEV1 measure?

Forced expiratory volume in 1 second — the volume of air forcefully exhaled in the first second of the FVC maneuver.

What does the FEV1/FVC ratio help distinguish?

It distinguishes obstructive disease (reduced ratio, e.g., asthma/COPD) from restrictive disease (preserved or increased ratio with reduced volumes).

What patient coaching is essential during a spirometry test?

Have the patient seal lips around the mouthpiece, take the deepest possible breath, then blast the air out as hard and fast as possible and continue exhaling fully; a nose clip is used.

What general patient prep is required before an abdominal ultrasound vs. a gallbladder ultrasound?

Abdominal/gallbladder ultrasound often requires fasting (NPO ~6–8 hours) to reduce bowel gas and ensure gallbladder distension.

What patient prep and safety screening is critical before an MRI?

Screen for and remove all metal (jewelry, implants, pacemakers, metal fragments); pacemakers and certain implants may be contraindications because of the strong magnetic field.

What key allergy must be screened before a contrast-enhanced CT or IV pyelogram?

Allergy to iodine/iodinated contrast media (and shellfish allergy is often asked); renal function (creatinine/eGFR) is also checked before contrast.

What patient preparation is typically required before a colonoscopy or barium enema?

Bowel prep — a clear liquid diet and laxative/cathartic regimen to empty the colon for clear visualization.