Forensic Dna Science By Cora De Ungria

Science in Society 26 April 2007

To ID or not to ID: that is the question Dr. Cora A. De Ungria DNA Analysis Laboratory UP Diliman QC

http://www.dnaforensic.org

Research ‘studious examination esp. experimentation aimed at discovery and interpretation of new facts, or the practical application of new theories…’ (SCIENTIFIC METHOD)

Research in Forensic Biotechnology

?

CSI PINAS?

Definitions • Biotechnology - any technology

that uses an organism or its parts to develop a new product or a new trait in an organism or to develop a new technique • Forensic - is the application of a broad spectrum of science to answer questions of interest to the legal system.

FORENSIC APPLICATIONS: • Investigations Civil/ criminal • Disputed parentage cases • Mass disasters

IDENTIFICATION!

Rape- homicide of 9 year old – July 10, 1999 People vs Vallejo, 9 May 2002 First case involving DNA evidence which reached the Supreme Court

Biology of a Human cell • Nucleus contains 23 pairs of chromosome •male 1-22 + XY; female 1-22 + XX • Mitochondrion/ mitochondria (pl): maternal

What is DNA? • Deoxyribonucleic acid • genetic blueprint of all living organisms • nitrogen bases G,A,T,C

Short Tandem Repeats (STR) ONE STR MARKER: TAGA

TAGA

TAGA

TAGA

TAGA

TAGA

TAGA

1 2

• size of marker = small • not code for proteins = not visible • highly variable in population

4/3

FBI Combined DNA Identification System

Properties of DNA •1 Chemical stability •2 Identity •3 Uniqueness

1. DNA in Courts

EC PROJECT: Human Rights and Democracy in Asia- Research, Training and Extension Service in Forensic DNA Analysis in the Philippines

1.Research to increase the standards of testing 2. Organize training courses for analysts, lawyers and judges 3. Conduct DNA tests for capital cases after SC review

STRATEGY: Yes to interview Search for biol. evidence: court, police, hospital, lawyers

Investigate ways to access evidence in the absence of judicial framework for the conduct of Post-Affirmation DNA tests

HOW DO YOU TEST FOR PATERNITY?

ALLEGED FATHER (AF)

MOTHER

CHILD

Case 1: Possibility of Paternity Alleged Father

Mother

Real father Child

or Chance match 66 77

88 99

66 99

Case 2: Exclusion of Paternity Alleged Father

10 7

10 7

Mother

Child

8 9

6 9

8 9

6 9

Absolutely not the real father

2. DNA in Investigations

DNA in Investigations • ‘Incorporating DNA Evidence in Routine

Examination of Child Sexual Assault cases’ • Worked with MDs of CPU units in Manila, Baguio, Cebu and Davao

39 cases

YES

male DNA

20

19

-

sperm detection

6

21

12

internal ejaculation

18

5

16

post-coital washing

28

8

3

NO

Unknown

3. Philippine Jurisprudence in Filiation Cases • Tijing vs Diamante (2001) • Herrera vs Alba (2005) • Agustin v Prollamante (2005) – (The growing sophistication of DNA technology is a “much needed equalizer” for “such ostracized and abandoned progeny” (i.e., illegitimate children)

Acknowledgments: •UP: NSRI, CPU, ASP, IHG •ADB, WB •European Commission •PCASTRD, DOST •NGOs (FLAG, PJPS) •PRC, NCIP regional