Forensic Science Techniques and Controls

This video tutorial covers the fifth part of identifying bodily fluids, focusing on blood. It explains species identification techniques to determine if blood is of human or animal origin. The video discusses the significance of species identification in forensic investigations, the role of antibodies and antigens, and the methods used, including primary and secondary binding assays. It also covers sample preparation and the use of controls in testing.

What is the primary goal of species identification in forensic science?

• To detect the presence of DNA in a sample

• To determine the age of a blood sample

• To identify the species origin of a biological fluid

• To measure the volume of a blood stain

How do antigens and antibodies interact in species identification?

• Antibodies convert antigens into proteins

• Antibodies bind specifically to antigens

• Antigens destroy antibodies

• Antigens and antibodies do not interact

Which of the following is a primary binding assay used in species identification?

• Radial immunodiffusion

• Immunoelectrophoresis

• ELISA

• Crossed immunoelectrophoresis

What is the main characteristic of immunochromatographic assays?

• They are slow and require laboratory settings

• They are rapid, specific, and sensitive

• They are only used for DNA analysis

• They require large sample volumes

Which technique is NOT a secondary binding assay?

• Immunoelectrophoresis

• Single immunodiffusion

• Double immunodiffusion

• ELISA

What is the purpose of using controls in sample preparation?

• To eliminate the need for further testing

• To increase the volume of the sample

• To change the color of the sample

• To provide a reference for comparison

What is a positive control in forensic analysis?

• A sample that is not used in testing

• A sample that is contaminated

• A sample with an unknown composition

• A sample known to contain the substance being tested for

What is the role of a negative control in forensic testing?

• To ensure the absence of the substance being tested for

• To increase the sensitivity of the test

• To provide a backup sample

• To confirm the presence of a substance

Which buffer is commonly used for extracting biological samples?

• Phosphate-buffered saline

• Sodium chloride

• Distilled water

• Ethanol

At what temperature is the extraction of biological samples usually performed?

• 100 degrees Celsius

• 37 degrees Celsius

• 25 degrees Celsius

• 0 degrees Celsius