BLOOD AND BLOODSTAIN

What blood spatter pattern is seen in the picture?

• Transfer/Contact
• Swipe
• Wipe
• Saturation

Both A and B antigens are found in...

• type A

• Type AB

• Type B

• Type O

Which confirmatory test is used to determine if a blood stain is human or not?

• leucomalachite

• Kastle-Meyer

• luminol test

• precipitin test

Answer explanation

Positive results must be confirmed with Precipitin Test. Once a presumptive test indicates that a stain may be blood, the serologist must confirm that it is human blood. Precipitin test identifies the presence of proteins that are found only in human blood.

The leucomalachite green presumptive test for blood is a catalytic test which is based on the peroxidase-like activity of hemoglobin.

The 3-stage Kastle–Meyer (KM) test has been used for decades as a rapid, presumptive test for blood. The test identifies the heme component of hemoglobin, which in the presence of hydrogen peroxide catalyzes the oxidation of the indicator phenolophthalin, turning it pink.

Forensic scientists spray luminol onto surfaces at crime scenes to detect invisible blood stains. Wherever the luminol touches blood, it glows, and the glow is bright enough to be photographed.

Blood cells responsible for oxygen distribution are called...

• Erythrocytes/red

• Leukocytes/red

• Erythrocytes/white

• Leukocytes/white

Answer explanation

Remember:

Red blood cells = Erythrocytes

Remember this: "REER"

White blood cells = Leukocytes

Type A+ blood can donate to

• A-

• A+

• AB-

• O+

Antibodies present in Type AB blood are...

• A

• B

• AB

• none

Antibodies present in Type A blood are...

• A

• B

• AB

• O

True or False:

An AB mother and OO father CANNOT have an OO child.

(Hint: work it out using a Punnett square)

• True

• False

Which presumptive test determines if a stain is blood by adding phenolphthalein and hydrogen peroxide and turns pink when positive?

• luminol

• leucomalachite

• kastle-meyer

Blood type is what type of forensic evidence?

• class

• individual