Can post-mortem blood be used for DNA profiling after

peri-mortem blood transfusion?

Jenna KausnerMay 20, 2011

PBIO 427

Introduction A controversial issue in forensics is if peri-

mortem blood transfusions can affect DNA profiling of the deceased.

Many people assume that the STR profile generated will be from the transfused blood instead of the deceased individual’s blood.

Hypothesized that donor leucocytes in administered blood will be detected in recipient blood.

Disadvantages

Other biological samples such as plucked hair or deep muscle are required for DNA profiling.

Leads to a higher cost and more time required to process samples.

Opposing views

Not supported by literature.

Previous studies have shown that blood transfusion does not affect the DNA profile of an individual, whether living or dead.

Summary of previous literature

Blood transfusion

Common to separate components of blood and not use whole blood

Packed RBC- RBC that have been separated from whole blood for transfusion purposes

Purpose Due to this persistent assumption, this

study tests whether STR profiling of a dead individual’s blood can be performed if the individual received large amounts of peri-mortem blood transfusions.

In addition, the affect of organ transplantation of DNA profiling was tested.

Sample collection

Five cases of deceased individuals who received massive peri-mortem blood transfusions were used to collect samples for DNA profiling.

Blood was collected from the iliac vein and samples were collected from psoas muscle tissue and plucked head hairs

Iliac vein and Psoas muscle

http://en.wikipedia.org/wiki/Psoas_major_muscle

http://en.wikipedia.org/wiki/Common_iliac_vein

Case histories of donated samples

Theoretical levels of DNA required for detection in RBC concentrate

Performed theoretical experiment to determine how much donor DNA needed to be present in order to be detected in blood.

Five units of leucocyte-depleted packed RBCs in additive solution were donated.

DNA extraction was performed and no DNA was detected using either quantification or STR profiling.

Detectable levels of cells Human dermis fibroblasts were

obtained from live cell culture grown from a donated breast reduction surgical specimen.

Serially diluted to 0, 1, 10, 100, 1000, and 10,000 cells and added to 200 μL aliuots of RBC concentrate.

Results of DNA profiling

Detectable levels of free DNA

Control genomic DNA K562 was purchased from Promega.

Serially diluted to 0, 0.01, 0.1, 1, 10 and 100 ng free genomic and added to blood cells.

Results of DNA profiling

Results of DNA profiling

The Blood Transfusion Service in the UK states that leucocyte depletion should be a minimum level of 99% so components contain 5x10^6 leucocytes per unit, which is about two cells per microliter.

This level could not be detected in this study.

DNA profiling of transfused patients

DNA was extracted from post-mortem blood using the QIAamp DNA Blood Mini Kit and from muscle and liver using the QIAamp DNA Tissue Mini Kit.

Ten plucked head hairs were washed with sterile water and ethanol, and put in a tube with lysis buffer and proteinase K then incubated for 24 hours at 37 ºC for digestion.

DNA profiling of transfused patients

DNA from hair was purified using phenol/chloroform/isoamyalcohol and then Microcon concentration.

How do you get DNA from hair? Did they extract from the root or the hair shaft?

DNA extraction from hair Small amounts of DNA can be extracted

from your hair.

When hair grows, the root is supplied with nutrients and cells at the bottom of the hair follicle are constantly dividing and forming new hair material.

Then, program cell death takes place as the hair grows, resulting in destruction of organelles.

Hair shaft

http://www.odec.ca/projects/2005/wali5s0/public_html/root.htm

DNA extraction from hair

Decomposed nuclei can be found in the hair shaft.

Sufficient DNA can be extracted from hair root.

Difficult to isolate DNA from hair shaft because it contains mostly highly degraded DNA from pycnotic nuclei.

Mitochondrial DNA?

DNA profiling of transfused patients

DNA profiling was performed on DNA extracted from hair, blood, and muscle from the deceased individuals.

Plucked hair was used as a reference to compare the other materials to.

Previous studies have shown DNA profiling of plucked hairs is not affected by many of the same issues in this study,

Results of STR profiling In all five cases, the DNA profile was

the same for the plucked head hairs and post-transfusion blood samples.

The only exception was the liver case where the DNA profile showed a mixture of two DNA sources.

Hypothesized to originate from the donor organ, but this information not available.

Results of STR profiling

Conclusion The current literature is supported by

this study by concluding that blood samples from recipients of massive blood transfusions can be used for DNA profiling.

In addition, blood can be collected from recipients of whole organ transplants, but this area needs to be investigated further.

References Graham, E. A. M., Toskos, M. & Rutty G. N.

(2007) Can post-mortem blood be used for DNA profiling after peri-mortem blood transfusion? Int J Legal Med, 121: 18-23.

http://www.odec.ca/projects/2005/wali5s0/public_html/root.htm

http://en.wikipedia.org/wiki/Common_iliac_vein http://en.wikipedia.org/wiki/

Psoas_major_muscle Muller, K., Klein, R., Miltner, E. & Wiegand, P.

(2007) Improved STR typing of telogen hair root and hair shaft DNA. Electrophoresis, 28: 2835f.