BIOL 3318 Final Exam Review (Official) - Forensic Serology (Semen)

What does sexual assault refer to?

Penetration by one person against another without any consent from the latter.

What is the difference between reportable and non-reportable sexual assault cases?

Non-Reportable -- Victim does not want to report yet, but has 5 years to decide

Reportable -- Reports assault after having SA kit complete and analyzed

What do sexual assault kits consist of and when are they examined?

Evidence collected during an SA investigation and are the first to be examined

What is semen?

Biological fluid produced by male gonads

What are the components of interest when examining seminal stains and how are each of them tested for?

Acid Phosphatase (Presumptive), p30/PSA (Presumptive), Flavins (Presumptive), Motile Spermatozoa (Confirmatory)

Why are alternate light sources (ALS) used in seminal stain examinations?

Helps locate possible stains on large clothing/bedding

Describe the parameters of Acid Phosphatase and why it is useful for semen identification.

-- Made from prostate gland

-- Degrades faster than sperm

-- Useful because it is found in semen in high amounts

Describe the AP Spot Test and its possible results.

AP forms Napthol from a-Napthol-P, reacting with Fast Blue B to form a purple color

-- (+) -- Purple in 1 Min

-- (-) -- No Change, Pink Change, or Change after 1 min

Describe the parameters of PSA/p30 and how it is located in semen.

-- Found in seminal plasma

-- Found via ABAcard p30 test (similar to HemaTrace)

How can the high dose hook effect in the ABAcard p30 test be overcome?

1:100 dilution of the sample followed by a rerun

How does the Christmas Tree Stain (NPR/PIC) confirm the sample is semen?

-- Is a differential stain

-- Stains the nucleus of the sperm with a red color

-- Midpiece and Tail are stained blue-green

-- Acrosomal Cap is less intensely red

Describe the three main portions of a sperm cell and their traits.

-- Head: Contains acrosome cap for sperm entry and houses DNA

-- Midpiece: Contains mitochondria

-- Tail: Motility, First to Breakdown

What are some of the problems that can arise during seminal stain examination?

-- Oligospermia (Low Sperm)

-- Azoospermia (No Sperm)

-- Contradictory Test Results (ex: AP and Microscopic Exam.)

What component is examined for in an oral assault case?

Amylase

How does male screening work and what system is used for results?

-- Detects quantity of male DNA in total sample DNA

-- Uses Plexor HY quantification system

What does the Direct to DNA approach entail?

Detects male DNA among female DNA