preview

Blood Types Lab Report

Decent Essays

Humans have different blood types that are called A, B, AB, and O. In addition to the four main blood types there are positive and negative types for each of the main blood types. This is determined from an antigen that is present on red blood cells called the Rh factor. In total there are 8 different blood types. Scientists identify these blood types by using different antigens, also called protein markers, that are on the surface of red blood cells in blood samples. The three different antigens that scientists use to identify the blood type are Antigen-A, Antigen-B and Antigen-Rh. In the body, antigens are recognized and attached to by antibodies. An antibody is a protein within the blood plasma that is used by the immune system to neutralize …show more content…

The antigen that is present in each blood type is different, which allows scientists to successfully determine blood types. For example, blood type A+ has antigen B; this means that if antigen-A or antigen Rh is added to the blood sample, being a foreign object, will cause it to clump or agglutinate. Forensic scientists use this technique to identify the blood type as the blood type is not affected by anything else such as disease, climate, living conditions, etc. This technique is performed by taking a blood sample and adding the three different antigens to it. By using blood type analysis, scientists are able to better study a case as they can eliminate individuals that do not own the blood type that was found at a crime scene. This allows them to move forward in their investigation and accurately solve a crime as they can identify the correct …show more content…

An easier method when analyzing hair samples is to use a microscope which has two steps. The first is to identify some characteristic features such as the root shape, cuticle scales, cortex color, medulla style, medulla thickens, medulla transparency, etc. Then these features would be compared to another hair of known origin. Hair grows out of the living cells in the epidermis – the outer layer of cells covering the head. The hair stays on the scalp due to the follicle that has arrector pili (associated muscles). One hair is composed of three different layers, the cuticle, the cortex and the medulla. The outer layer is a layer of scales called the cuticle. The cortex is the middle layer and makes up the majority of the hair mass. The innermost canal is the medulla which in humans can either be continuous or discontinuous. Pigments are absent from the cuticle but can be found in the other two layers. Due to hair growing from follicles in the skin, there are some materials that are occasionally incorporated into the making of the hair. This is very important in forensic science because hair analysis could answer questions that no other evidence may be able to give. For example, if a person were to be poisoned, some traces may be found within the hair sample, even after it has left any organs within the body of the victim. Hair sample analysis is also very important when

Get Access