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100+ Free ABC-BIO Practice Questions

Pass your ABC Biological Evidence Screening Certification (ABC-BIO) exam on the first try — instant access, no signup required.

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Key Facts: ABC-BIO Exam

50 + 10

Scored + Pilot Items

ABC Biological Screening page

1 hr 30 min

Time Limit

ABC Biological Screening page

$250

Exam Fee

ABC Application Process

$75

Application Fee

ABC Application Process

FKE

Prerequisite Exam

ABC Certification Scheme

5 years

Recertification Cycle

ABC Certification Scheme

90 days

Application Lead Time

ABC Application Process

In person

Delivery Mode

ABC Certification page

ABC-BIO is the American Board of Criminalistics Biological Evidence Screening certification for active forensic-lab screeners. The closed-book in-person exam runs up to 1 hour 30 minutes and contains 50 scored items plus 10 unscored pilot items (60 total). The application fee is $75 and the exam fee is $250; applications must be submitted at least 90 days before the sitting and remain valid for 24 months. ABC does not publish the numeric cut score. Recertification runs on a 5-year cycle with annual maintenance fees and signed Rules of Professional Conduct. Candidates must hold (or be approved for) the ABC Foundational Knowledge Exam, work a screening bench, and submit two professional references.

Sample ABC-BIO Practice Questions

Try these sample questions to test your ABC-BIO exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1A bench analyst dabs a stain with filter paper, adds phenolphthalin reagent, then hydrogen peroxide, and the paper turns bright pink within seconds. What does this result indicate?
A.Confirmed presence of human blood
B.Presumptive positive for blood (peroxidase activity)
C.Confirmed presence of menstrual blood
D.Eliminates blood from further consideration
Explanation: Kastle-Meyer (phenolphthalein) is a catalytic presumptive blood test relying on peroxidase activity of heme to oxidize the indicator. A rapid pink color is presumptive only; species and confirmatory testing are still required.
2Why must hydrogen peroxide be added AFTER the phenolphthalin reagent during a Kastle-Meyer test rather than simultaneously?
A.To prevent false-positive color from atmospheric oxidation of reduced phenolphthalin
B.To dissolve the dried blood
C.To buffer the reaction to neutral pH
D.To denature contaminating proteins
Explanation: The reagent uses leuco (reduced) phenolphthalin which slowly oxidizes in air to pink phenolphthalein. Adding peroxide separately confirms that any pink color is driven by the heme-catalyzed peroxidase reaction, not by ambient oxidation.
3An analyst sprays luminol on a cleaned floor and photographs a faint blue-white chemiluminescence. Which statement most accurately describes the limitation of this result?
A.It confirms human blood at the location
B.It is species-specific to mammals
C.It is a presumptive reaction prone to false positives from bleach, copper, and some plant peroxidases
D.It precludes any further DNA recovery
Explanation: Luminol catalyzed by heme generates chemiluminescence, but bleach, certain metals (copper, iron salts), and horseradish peroxidases produce false positives. It is presumptive only and must be followed by confirmatory and human-specific testing.
4Which presumptive blood reagent is marketed as more sensitive than luminol while producing less interference from bleach and copper backgrounds?
A.Bluestar Forensic
B.Leucomalachite green
C.Hemastix
D.Tetramethylbenzidine (TMB)
Explanation: Bluestar Forensic is a luminol-class reagent reformulated for brighter, longer-lasting chemiluminescence with reduced sensitivity to common interferents such as bleach. It still requires confirmatory testing.
5A Takayama test on a suspected bloodstain produces salmon-pink rhombic crystals under the microscope. What does this confirm?
A.Human blood specifically
B.Hemoglobin (hemochromogen crystals)
C.Menstrual rather than peripheral blood
D.Presence of intact red blood cells
Explanation: Takayama produces pyridine ferroprotoporphyrin (hemochromogen) crystals from heme, confirming the presence of hemoglobin. It is not species-specific; human identification requires an immunological test such as ABA card/HemoTrace.
6Teichmann crystal testing relies on the formation of which characteristic crystal?
A.Hemin (chloride of heme) — brown rhombic crystals
B.Hemochromogen — pink rhombic crystals
C.Calcium oxalate — colorless dipyramidal crystals
D.Cholesterol — birefringent plates
Explanation: Teichmann's reaction uses glacial acetic acid plus a halide to convert heme to hemin (ferriprotoporphyrin chloride), producing brown rhombic crystals. Like Takayama it confirms heme/hemoglobin but is not species-specific.
7Which immunochromatographic test confirms that a presumptive bloodstain is of HUMAN (or higher-primate) origin by detecting human hemoglobin?
A.ABA card / HemoTrace (human hemoglobin)
B.RSID-Semen (semenogelin)
C.RSID-Saliva (alpha-amylase)
D.Phadebas press test
Explanation: ABA cards and HemoTrace are lateral-flow immunoassays for human hemoglobin and provide species-specific confirmation when used after a presumptive peroxidase test. They cross-react with some higher primates.
8Which substrate is MOST likely to cause a false positive on the Kastle-Meyer presumptive blood test?
A.Vegetable matter containing horseradish peroxidase
B.Distilled water
C.Glass with no biological residue
D.Dried plastic
Explanation: Plant peroxidases (notably horseradish) catalyze the same peroxide-driven oxidation of phenolphthalin, producing a pink color in the absence of blood. Substrate controls are required to manage this risk.
9A casework cutting is placed in a tube with sodium acetate buffer and brentamine-coupled napthyl phosphate; a purple color develops within 30 seconds. What is the BEST interpretation?
A.Strong presumptive positive for acid phosphatase consistent with semen
B.Confirmatory positive for spermatozoa
C.Positive for prostate-specific antigen
D.Negative result
Explanation: The reagent is the classic acid phosphatase (AP) presumptive test for semen. Color development within ~30 seconds is considered a strong presumptive due to the high AP concentration in seminal fluid. Confirmation still requires microscopic sperm or a confirmatory protein test.
10Acid phosphatase reaction times longer than 1-2 minutes are interpreted cautiously because AP activity above background can also originate from which source?
A.Vaginal secretions, feces, and some plant materials
B.Pure tap water
C.Nitrile gloves
D.Aluminum foil packaging
Explanation: Acid phosphatase is also present at lower levels in vaginal fluid, fecal material, fungi, and certain plants, so delayed weak reactions are not specific to semen. Rapid intense reactions remain a strong presumptive indicator.

About the ABC-BIO Exam

ABC-BIO is the American Board of Criminalistics specialty certification for forensic biologists and screeners who locate, identify, and prepare biological evidence for downstream DNA analysis. The closed-book in-person exam contains 50 scored multiple-choice questions plus 10 unscored pilot items and runs up to 1 hour and 30 minutes. Candidates must hold or be approved for the ABC Foundational Knowledge Exam (FKE) and actively work a screening bench performing presumptive and confirmatory body-fluid testing.

Questions

60 scored questions

Time Limit

Up to 1 hour, 30 minutes

Passing Score

Not published (scaled cut score set during exam development)

Exam Fee

$75 application fee + $250 examination fee (American Board of Criminalistics)

ABC-BIO Exam Content Outline

Presumptive + confirmatory

Blood Identification

Kastle-Meyer/phenolphthalein, leucomalachite green, Bluestar/luminol peroxidase chemistry, Takayama and Teichmann crystals, ABA card/HemoTrace for human hemoglobin.

Presumptive + confirmatory

Semen Identification

Acid phosphatase color-change kinetics, Christmas tree (nuclear fast red + picroindigocarmine) sperm visualization, RSID-Semen semenogelin, p30 PSA.

Miscellaneous body fluids

Saliva, Urine, Feces, Menstrual Blood, Vaginal

Phadebas alpha-amylase, RSID-Saliva, Jaffe creatinine, urobilinogen, D-dimer for menstrual blood, glycogen-rich vaginal epithelial cells.

Locating biological evidence

Search Techniques and ALS

Alternate light source at 450 nm with orange filter for semen fluorescence, substrate selection, cutting/swabbing techniques, bindle packaging, drying.

Pre-DNA workflow

Extraction and Sample Preparation

Differential extraction of sperm vs epithelial fractions for sexual-assault evidence, hair root vs shed hair HCRT, microscope morphology.

Lab governance

Quality Assurance, Safety, and Reporting

Positive/negative controls, reagent verification, ISO/IEC 17025 + ANAB accreditation, OSAC Biology, chain of custody, 29 CFR 1910.1030 PPE, court testimony limits.

How to Pass the ABC-BIO Exam

What You Need to Know

  • Passing score: Not published (scaled cut score set during exam development)
  • Exam length: 60 questions
  • Time limit: Up to 1 hour, 30 minutes
  • Exam fee: $75 application fee + $250 examination fee

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

ABC-BIO Study Tips from Top Performers

1Download and outline the ABC Biological Evidence Screening Certification Scheme, Job Description, Examination Blueprint, and Study Guide; map every listed duty/task to a study session.
2Memorize the presumptive vs confirmatory framework for each fluid, including the specific reagent (e.g., Christmas tree = nuclear fast red + picroindigocarmine; HemoTrace = human Hgb).
3Drill ALS wavelengths and barrier filters; semen fluoresces near 450 nm with an orange filter, while blood absorbs and appears dark.
4Practice acid phosphatase color-change kinetics and how rapid reactions versus delayed reactions are interpreted before moving to confirmatory testing.
5Build a controls checklist: positive control, negative/reagent blank, substrate control, and known body-fluid standards must accompany every batch.
6Review 29 CFR 1910.1030 bloodborne-pathogens PPE, biohazard packaging, drying, refrigeration vs freezing, and bindle packaging for trace material.
7Study differential extraction sperm/epithelial fractions and when to skip extraction (e.g., HCRT for hair root vs shed hair, microscope-only items).
8Read NAS 2009 cautions on microscopic hair comparison and OSAC Biology standards so you can frame statements at court within current limitations.

Frequently Asked Questions

What is the ABC Biological Evidence Screening certification?

ABC-BIO is the American Board of Criminalistics specialty credential for forensic biologists who screen evidence and prepare samples for DNA analysis. It validates competency in body-fluid identification, ALS searches, and pre-amplification sample handling, but it does not by itself certify a DNA analyst for amplification or interpretation.

How many questions are on the ABC-BIO exam and how long is it?

The exam contains 50 scored multiple-choice questions plus 10 unscored pilot questions, for 60 total items. Candidates have up to 1 hour and 30 minutes. ABC delivers the exam in person only at specified testing locations; no remote proctoring is available.

What is the passing score for ABC-BIO?

ABC does not publish the numeric cut score. The passing score is determined during exam development and pilot testing and is kept confidential. Candidates receive a pass/fail result within about 30 days of the exam date.

What does ABC-BIO cost?

The application fee is $75 and the examination fee is $250 per sitting. Annual maintenance fees apply to keep certification active after passing. Applications must be submitted at least 90 days before the desired exam date and remain valid for 24 months after approval.

Do I need to pass the FKE before taking ABC-BIO?

Yes. ABC-BIO is a specialty exam in the ABC certification scheme; candidates must hold or be approved to sit for the Foundational Knowledge Exam (FKE/GKE) in addition to working at a forensic-science service provider performing biological screening.

What experience do I need to apply?

You must be actively employed at a forensic-science service provider performing biological evidence screening work, including presumptive and confirmatory testing for blood, semen, and miscellaneous body fluids. Two professional references and a signed Rules of Professional Conduct acknowledgment are required with the application.

How often must ABC-BIO be recertified?

ABC certifications run on a 5-year recertification cycle. Certificants must pay annual maintenance fees, submit signed Rules of Professional Conduct each year, and complete continuing-education and professional-development requirements before the recertification deadline.

Can ABC-BIO be taken online or remotely?

No. ABC examinations are only offered in person at specified testing locations. Remote proctoring is not available, so candidates must arrange travel to an approved site.

What presumptive and confirmatory tests appear on ABC-BIO?

Expect Kastle-Meyer/phenolphthalein, leucomalachite green, Bluestar/luminol, Takayama, Teichmann, and ABA card/HemoTrace for blood; acid phosphatase, Christmas tree stain, RSID-Semen, and p30 for semen; Phadebas alpha-amylase and RSID-Saliva for saliva; and Jaffe creatinine, urobilinogen, D-dimer, and glycogenated vaginal cells for the remaining fluids.

Why is ALS at 450 nm with an orange filter important?

Semen fluoresces strongly under blue light near 450 nm when viewed through an orange (approximately 555 nm long-pass) barrier filter. Screeners use this wavelength to triage large items and locate candidate semen stains before applying acid phosphatase or RSID-Semen confirmatory tests.