Category Archives: Blood Examination

Blood Examination, Forensic Science, Forensic Serology

Electrophoresis Test

25th June 2019 Forensic Science Leave a comment

By @forensicfield

What is Electrophoresis Test?

Electrophoresis is being used for the separation of various enzyme system.

There are two type of electrophoretic method have been recommended for identification of blood stains;-

1] Separation and identification of hemoglobin by electrophoresis, and,
2] Separation and identification of serum proteins by immunoelectrophoresis.

Immunoelectrophoresis is a two‐stage process:

1.} Electrophoresis is conducted, and;
2.} Immunoprecipitation using antibodies against specific proteins.

Resolution is improved by staining the proteins.

The technique is widely used to identify monoclonal immunoglobulins (M‐components) in serum and urine.

It’s Uses In Forensics

It’s a Confirmatory test for blood.

Basis Of The Test

This process involves the separation of Marker Proteins that are found on the surface of red blood cells.

Indication for the Presence of Blood

Electrophoresis can be used to isolate and compare DNA, Blood proteins and inorganic substances.

How To Perform This Test ?

For Analyzing of Proteins

Pic Courtesy: https://www.sciencedirect.com/topics/neuroscience/gel-electrophoresis

Drawbacks

The disadvantages are that gels can melt during electrophoresis, the buffer can become exhausted, and different forms of genetic material may run in unpredictable forms.

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Blood Examination, Forensic Science, Forensic Serology

Spectrophotometry Test

25th June 2019 Forensic Science Leave a comment

By @forensicfield

What is Spectrophotometry Test?

Spectrophotometry is measuring intensity of light in a part of the spectrum as transmitted by particular substances.

Spectrophotometry Test is based on the identification of hemoglobin and its derivatives (such as; methamoglobin, carboxyhemoglobin, oxyhemoglobin.) through their specific absorption spectra.

It’s Uses In Forensics

It’s a Confirmatory test for blood.

This method was considered one of the most conclusive test for the identification of blood stains.

Basis Of The Test

Hemoglobin and its derivatives exhibit characteristic bands of absorption at specific wavelength , which can be observed by spectrophotometer.

Indication for the Presence of Blood

It produced specific absorption spectra for hemoglobin and its derivative for identification of blood.

How To Perform This Test ?

A complex system of band is present because of heme (part of hemoglobin) in the near UV and Visible region of spectrum.

Sometimes they differs from derivative to derivative of heme portion but they all have common strong absorption band at 400-425 nm which is also known as Soret Band.