FREE CST Study Guide 2026: A Complete, NBSTSA-Aligned Walkthrough

This free CST study guide walks through the highest-yield content the NBSTSA Certified Surgical Technologist exam tests, organized by the three domains of the official content outline — Perioperative Care, Ancillary Duties, and Basic Science.^[1]

It is interactive, not a wall of text: every domain has worked OR scenarios, instrument and sterilization tables, labeled diagrams, and built-in flashcards, taught the way the CST is actually tested — the scrub-role skills of sterile technique, instruments, counts, hemostasis, specimens, and the anatomy, microbiology, and pharmacology behind them.

Read it domain by domain, then round out your prep with our practice questions and flashcards. The CST credential is awarded by the NBSTSA to graduates of a CAAHEP- or ABHES-accredited surgical technology program.

CST Exam Snapshot

Perioperative Care is 97 of the 150 scored items — and Intraoperative Procedures alone is 68, nearly half the whole exam. That is where to spend most of your study time. Ancillary Duties (23 items) and Basic Science (30 items) round out the rest.^[1]

Percentages are the share of the 150 scored items in each official subsection and are rounded, so they do not sum to exactly 100. The three top-level domains group these subsections: Perioperative Care (97), Ancillary Duties (23), and Basic Science (30).^[1]

How the CST Exam Is Built

The CST exam follows the NBSTSA content outline, which groups every scored item into three domains. This guide teaches all eight official subsections, organized into those three study modules so the structure matches the blueprint exactly.^[1]

• Perioperative Care (97 items) — Preoperative Preparation (19), Intraoperative Procedures (68), and Postoperative Procedures (10): the heart of the scrub role.
• Ancillary Duties (23 items) — Administrative & Personnel (7) and Equipment Sterilization & Maintenance (16): the responsibilities around the case.
• Basic Science (30 items) — Anatomy & Physiology (18), Microbiology (6), and Surgical Pharmacology (6): the science behind the procedures.

Everything on the exam connects back to one mission: keeping the patient safe by maintaining a sterile field, anticipating the surgeon’s needs, and preventing infection and retained items. The CST is certified to work in the scrub role under the surgeon’s direction — not to make independent surgical decisions.

Perioperative Care

Perioperative Care is the largest domain at 97 of 150 scored items — roughly two-thirds of the exam.^[1] It spans everything from preparing the patient and the room, through the procedure itself, to postoperative care. Master the scrub-role fundamentals here and you own the bulk of the exam.

Preoperative Preparation (19 items)

Before the case, the CST verifies the patient with two identifiers, confirms the informed consent is signed and matches the planned procedure and site, and helps pull the case from the surgeon’s preference card. The time-out — the final step of the Universal Protocol — is a team pause before incision to verify the correct patient, procedure, and site/side; it prevents wrong-site surgery, a sentinel never event.^[8]

Skin prep: remove hair only if it interferes (with clippers, never a razor), then apply an antiseptic — chlorhexidine gluconate (longest residual), povidone-iodine, or alcohol-based — starting at the incision and moving outward in expanding circles, clean to dirty, never returning a used sponge to the center. Let alcohol-based preps dry fully before draping or electrosurgery, because pooled prep is a fire and burn hazard.^[5]

Sterile Technique & Asepsis

Sterile asepsis is the foundation of the whole exam. The governing rule is simple: sterile touches only sterile — any contact with an unsterile item is contamination.

Know the sterile boundaries of a gown and field cold: a gown is sterile only from the chest to the waist in front and at the sleeves; tables are sterile only at table level; and the outer 1 inch of any drape is an unsterile boundary. Hands stay above the waist and in sight.^[4]

The CST practices closed gloving (hands stay inside the gown cuffs) for self-gloving, and applies a surgical conscience — the honesty to recognize and report any break in technique, even when unobserved. Strike-through (moisture wicking through a drape or gown) contaminates the barrier.

Positioning, Prep & Draping

The surgical position gives access to the site while protecting the patient. Pad bony prominences and nerves, maintain alignment, and protect the eyes, genitalia, brachial plexus, and peroneal nerve. Drapes are applied from the incision site outward and are never moved back toward the field once placed.

Surgical Instruments

Instrument knowledge is the densest part of Intraoperative Procedures. Group instruments by function — cutting/dissecting, grasping/holding, clamping/occluding, retracting/exposing, and suctioning/accessory — then learn the specific names and uses within each family. Pass each instrument firmly into the surgeon’s palm, ready to use, so they need not look away from the field.

Load a blade with a needle holder (never fingers), grasping the dull edge and sliding it on pointing away from you. Differentiate the look-alikes: Allis has teeth that grip firmly while Babcock is atraumatic for delicate tubular tissue like bowel; mosquito hemostats are smallest, then Crile/Kelly, then Pean.

Counts & Specimens

Surgical counts of sponges, sharps, and instruments prevent a retained surgical item — a preventable never event. Count at five trigger points and reconcile every number. Sponges are radiopaque so a retained one shows on X-ray; never use them as dressings.^[4]

Specimens:the scrub keeps each specimen identified and isolated, then hands it to the circulator, who labels it with the patient’s name and the exact source. A frozen section and a culture go off fresh — never in formalin — while routine specimens may be preserved per policy. A lost or mislabeled specimen can mean a repeat procedure or a missed diagnosis.^[4]

Hemostasis & Electrosurgery

Hemostasis — controlling bleeding — is achieved mechanically (pressure, ligatures, clips, staples, bone wax, tourniquet), thermally (electrosurgery, laser, harmonic scalpel), or chemically (thrombin, Gelfoam, oxidized cellulose). The CST anticipates which the surgeon will need and keeps hemostatic supplies ready.

Electrosurgery (the “Bovie”) uses high-frequency current to cut and coagulate. In monopolar mode the current travels from the active pencil through the patient to a dispersive return pad; in bipolar mode it passes only between the two forceps tips, so no pad is needed. Place the dispersive pad over clean, dry, well-vascularized muscle, away from bony prominences, scars, hair, and implants, to prevent burns.^[4]

Minimally Invasive & Robotic Surgery

In laparoscopy, the surgeon operates through small ports using a camera and long instruments, with the abdomen insufflated with CO₂ to create the pneumoperitoneum. CO₂ is chosen because it is noncombustible, highly soluble in blood (so emboli are rare), and inexpensive.

A trocar within a cannula creates each port; the Veress needle (closed) or Hasson (open) technique establishes access. In robotic surgery the CST drapes the arms, exchanges instruments, and assists at the bedside while the surgeon operates from a console.

Wounds & Wound Healing

The CDC wound classification grades contamination from Class I (clean) to Class IV (dirty/infected) and guides antibiotics and closure. Wounds heal by first intention (clean approximated edges), second intention (left open to granulate), or third intention (delayed closure). Knowing the layers being closed lets the scrub anticipate the right suture for each tissue.^[5]

Postoperative Procedures (10 items)

At case end, the team completes the final counts, hands off the specimen, accounts for sharps, applies the dressing after the drapes are removed, and breaks down the field safely (sharps into puncture-proof containers). The patient recovers in the PACU, monitored for airway, vital signs, and level of consciousness. Watch for postoperative complications: dehiscence (wound-layer separation) and evisceration (organ protrusion — an emergency; cover with sterile saline-moistened dressings and notify the surgeon), hemorrhage, SSI, atelectasis, DVT/PE, ileus, and urinary retention.^[8]

Ancillary Duties

Ancillary Duties is 23 of 150 scored items.^[1] It covers the responsibilities around the case: administrative and personnel duties, and the decontamination, sterilization, and maintenance of instruments and equipment. Equipment Sterilization & Maintenance (16 items) is the larger and more heavily tested half.

Administrative & Personnel (7 items)

The CST works within a defined scope of practice and the chain of command, documents accurately (counts, implants with lot/serial numbers, specimens, medications), protects patient confidentiality under HIPAA, and follows OR attire and traffic rules in restricted areas. The surgeon is responsible for obtaining informed consent; the team verifies it is signed, complete, and correct. Supplies are managed with par levels and stock rotation by expiration (FIFO).

Decontamination & Spaulding

Instrument processing always flows in one direction — dirty → clean → sterile — and never backward. Decontamination comes first: cleaning removes blood and debris, because organic soil shields microbes from any sterilant. The Spaulding classification sets how thoroughly an item must be reprocessed based on how it is used.^[6]

Sterilization Methods

Sterilization destroys all microbial life including spores; disinfection does not reliably kill spores. Match the method to the item: steam for heat- and moisture-stable items, and a low-temperature method for delicate or heat-sensitive items.^[6]

Use immediate-use steam sterilization (formerly “flash”) sparingly — the item is not packaged for storage and must be used at once. Load the sterilizer so the sterilant reaches all surfaces: open box locks and ratchets, do not overload, and place basins on edge to drain.

Sterilization Monitoring & Storage

Three layers of monitoring confirm a load. A biological indicator (a spore test) is the only true proof of sterility; a chemical indicator proves only that an item was exposed to the sterilant; and mechanical indicators (the printout of time, temperature, and pressure) confirm the cycle ran in spec. A Bowie-Dick test checks air removal in prevacuum steam sterilizers daily.^[6]

Sterile packages are stored clean, dry, and off the floor, and follow event-related sterility— a package stays sterile until an event (a tear, wetness, or a drop) compromises it. Always inspect a package’s integrity and indicator before opening it onto the field.

Basic Science

Basic Science is 30 of 150 scored items — anatomy and physiology (18), microbiology (6), and surgical pharmacology (6).^[1] This is the science the scrub uses to anticipate the surgeon, prevent infection, and handle medications safely on the field.

Anatomy & Physiology (18 items)

Know directional terms and planes, the body cavities and their serous membranes (pericardium, pleura, peritoneum), and the structures of each system that is operated on. Anatomy lets you anticipate the instruments, sutures, and retractors at each step — for example, the layers of the abdominal wall in the order they are incised, or the structures of Calot’s triangle in a cholecystectomy.^[8]

Layers of a midline abdominal incision, surface inward: skin → subcutaneous (Camper’s and Scarpa’s fascia) → muscle/fascia (rectus sheath or oblique muscles) → transversalis fascia → preperitoneal fat → peritoneum. Closure generally reverses this, layer by layer.

Microbiology (6 items)

Microbiology underpins infection control. Classify bacteria by Gram stain (Gram-positive = purple, thick wall; Gram-negative = pink, thin wall + outer membrane) and by shape (cocci, bacilli, spirilla).

Know that spores (Clostridium, Bacillus) resist heat and chemicals — which is exactly why sterilization must kill them. Break the chain of infection with sterile technique, hand hygiene, and standard precautions.^[7]

Surgical Pharmacology (6 items)

On the sterile field the CST handles medications directly, so labeling and verification are safety-critical: label every medication and solution immediately (even when there is only one) and verify the drug, strength, and expiration aloud with the circulator. Know the anesthesia categories, the common local anesthetics, and the high-alert agents.^[8]

How to Use This Study Guide

Work through the guide one domain at a time. After each domain, check it off in the contents to raise your exam-readiness score, then drill the same content in our free practice questions and flashcards — active recall and timed practice are what move knowledge into exam-day performance.

• Weight your time by item counts. Perioperative Care is 97 of 150 items; Intraoperative Procedures alone is 68 — start there.
• Drill instruments relentlessly. Recognizing instruments and their uses is the densest, most-tested content on the exam.
• Lock in the safety rules. Sterile boundaries, the five count points, Spaulding, and the biological-vs-chemical indicator distinction appear again and again.
• Don’t neglect Basic Science. Anatomy (18 items) is as large as the entire Postoperative + Microbiology + Pharmacology content combined.
• Then prove it. When a domain feels easy, confirm it with our practice questions and flashcards.

Common questions CST candidates search and get asked — each answered briefly and backed by an official source (NBSTSA, AST, AORN, CDC, or NIH). Tap any card to test yourself.

CST Glossary

Key CST terms in one place. Hover any dotted term throughout the guide for its definition; the full list is below.

CST

Certified Surgical Technologist — the NBSTSA credential for the surgical technologist who prepares the OR and assists during surgery, primarily in the scrub role.

NBSTSA

National Board of Surgical Technology and Surgical Assisting — the body that develops and awards the CST credential and sets eligibility.

AST

Association of Surgical Technologists — the professional association for surgical technologists; it provides continuing education and processes CST recertification.

asepsis

The absence of pathogenic microorganisms; surgical (sterile) asepsis aims for the total absence of all microbes on the sterile field.

sterile field

The area created with sterile drapes and supplies around the surgical site; only sterile items and sterile-gowned/gloved persons may contact it.

surgical conscience

The professional honesty and self-discipline to maintain sterile technique and report any break in sterility, even when unobserved.

strike-through

Moisture wicking through a drape, gown, or wrapper that carries microbes to a sterile surface, contaminating it.

time-out

A pause before incision in which the team verifies correct patient, correct procedure, and correct site/side, per the Universal Protocol, to prevent wrong-site surgery.

scrub role

The sterile CST who maintains the sterile field, sets up the back table and Mayo stand, passes instruments, and tracks counts.

circulator

The non-sterile team member outside the field who manages the room, obtains supplies, documents, and assists with counts and patient care.

Mayo stand

A small sterile stand placed over the patient that holds the instruments in immediate use.

back table

The large sterile table holding the bulk of the instruments, sponges, sutures, and supplies organized by the scrub.

surgical count

A counted reconciliation of sponges, sharps, and instruments performed at set times to prevent a retained surgical item.

retained surgical item

An item unintentionally left in the patient (a sponge, needle, or instrument); a preventable 'never event.'

radiopaque

Containing a marker that shows up on X-ray; surgical sponges are radiopaque so a retained sponge can be located.

hemostasis

The control of bleeding, achieved by mechanical (pressure, ligatures, clips), thermal (electrosurgery, laser), or chemical (thrombin, Gelfoam) means.

electrosurgery

Use of high-frequency electrical current to cut tissue and coagulate bleeding; monopolar uses a return pad, bipolar passes current between forceps tips.

dispersive pad

The grounding/return electrode for monopolar electrosurgery, placed over clean, dry, well-vascularized muscle to prevent burns.

surgical smoke

The plume from electrosurgery or laser that can carry viable cells, viral DNA, and toxins; evacuated with a smoke evacuator and high-filtration masks.

frozen section

A specimen sent FRESH (not in formalin) for rapid intraoperative pathology while the patient is still under anesthesia.

formalin

A preservative (formaldehyde solution) for routine specimens; never used for culture or frozen-section specimens.

laparoscopy

Minimally invasive surgery through small ports using a camera (laparoscope) and long instruments, with the abdomen insufflated with CO₂.

trocar

A pointed or blunt instrument within a cannula used to puncture the body wall and create a laparoscopic port.

pneumoperitoneum

The CO₂-insufflated working space created in the abdomen for laparoscopy.

first intention

Primary wound healing where clean, approximated edges heal quickly with minimal scarring.

second intention

Wound healing where an open wound granulates from the bottom up; used for contaminated/infected wounds, with more scarring.

dehiscence

Partial or complete separation of the layers of a surgical wound.

evisceration

Protrusion of internal organs through an open surgical wound — a surgical emergency.

decontamination

The cleaning and disinfection that removes blood, debris, and microbes so an item is safe to handle before sterilization.

Spaulding classification

A system sorting items as critical (sterilize), semicritical (high-level disinfect), or noncritical (low/intermediate disinfect) by infection risk.

sterilization

A process that destroys ALL microbial life, including spores; required for critical (surgical) items.

disinfection

A process that destroys most pathogens but does not reliably kill spores.

autoclave

A steam-under-pressure sterilizer; the most common, economical method for heat- and moisture-stable items.

biological indicator

A vial of resistant bacterial spores processed and incubated to confirm a sterilizer actually killed spores — the only true proof of sterility.

chemical indicator

A tape, strip, or integrator that changes color to show an item was EXPOSED to the sterilant; it does NOT prove sterility.

Bowie-Dick test

A daily air-removal and steam-penetration test for prevacuum steam sterilizers, run in an empty chamber.

event-related sterility

The principle that a package stays sterile until an event (tear, wetness, drop) compromises it — not a fixed expiration date.

IUSS

Immediate-use steam sterilization (formerly 'flash'): for an item needed at once; not packaged for storage and must be used immediately.

Gram stain

A staining method classifying bacteria as Gram-positive (purple, thick wall) or Gram-negative (pink, thin wall + outer membrane); guides antibiotics.

spore

A dormant, highly resistant bacterial form (Clostridium, Bacillus) that survives heat and chemicals; sterilization must kill spores.

chain of infection

The six links — agent, reservoir, portal of exit, transmission, portal of entry, susceptible host — needed for infection; break any link to prevent spread.

standard precautions

Treating all blood and body fluids as potentially infectious for every patient: hand hygiene, gloves, gowns, and eye protection.

local anesthetic

A drug (lidocaine, bupivacaine) that blocks nerve conduction in a region; epinephrine may be added to prolong action and reduce bleeding.

malignant hyperthermia

A life-threatening reaction to volatile anesthetics or succinylcholine: rising end-tidal CO₂, rigidity, tachycardia, later high fever; treated with dantrolene.

dantrolene

The specific antidote for malignant hyperthermia; the team rapidly reconstitutes many vials.

heparin

An anticoagulant used on the field (e.g., vascular cases) to prevent clotting; reversed by protamine sulfate.

informed consent

The patient's voluntary agreement to a procedure after the surgeon explains its risks, benefits, and alternatives; the team verifies it is signed and correct.

wound classification

The CDC system grading a surgical wound from Class I (clean) to Class IV (dirty/infected) by contamination level and infection risk.

CST Study Guide FAQ

References

1. 1.National Board of Surgical Technology and Surgical Assisting (NBSTSA). “CST Examination Content Outline (effective Jan 1, 2023).” NBSTSA. ↑
2. 2.National Board of Surgical Technology and Surgical Assisting (NBSTSA). “CST Certification & Eligibility.” NBSTSA. ↑
3. 3.Association of Surgical Technologists (AST). “Continuing Education Policies & CST Recertification.” AST. ↑
4. 4.Association of periOperative Registered Nurses (AORN). “Guidelines for Perioperative Practice (sterile technique, RSI prevention, electrosurgery, specimens).” AORN. ↑
5. 5.Centers for Disease Control and Prevention (CDC). “Guideline for the Prevention of Surgical Site Infection.” CDC. ↑
6. 6.Centers for Disease Control and Prevention (CDC). “Guideline for Disinfection and Sterilization in Healthcare Facilities.” CDC. ↑
7. 7.Centers for Disease Control and Prevention (CDC). “Isolation Precautions & Transmission of Infection.” CDC. ↑
8. 8.National Institutes of Health / National Library of Medicine. “StatPearls & MedlinePlus Clinical Reference (anatomy, microbiology, pharmacology).” NIH/NLM. ↑

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