PDF-HHMI Hughes Undergraduate Biological Science Education Initiative Blood Stain Analysis

They also find stains that could be either blood or some other similar substance like reddishbrown paint What other things can you think of that might look like blood How would you test a stain to see if it is blood Have you ever used hydrogen perox. A stain is a chemical reaction between the staining agent and the fibers and finishes of a fabric There is no single product or method for removing all stains because the chemical makeup of each stain and agent is unique These directions have been t Objective: to understand how blood stains can give forensic scientists information about a crime.. blood. Blood is what moves oxygen around our body from the lungs to the organs that need oxygen and then back the lungs for more oxygen.. and . Evidence Collection. Physical Evidence. Any and all objects that can establish that can establish that a crime has or has not been committed or can link a crime and its victim or perpetrator. In order to be useful it must be collected, preserved and properly analyzed by forensic experts. Dr. Shiuli, Forensic Medicine & Toxicology, KGMU. Different stains having . Medicolegal. importance. Blood. Seminal fluid. Vaginal discharge. Saliva. Faecal. stain. Urine. Dr. Shiuli, Forensic Medicine & Toxicology, KGMU. A stain is a substance that adheres to a cell, giving the cell color. .. The presence of color gives the cells significant contrast so are much more visible. . Different stains have different affinities for different organisms, or different parts of . Dr. Shiuli, Forensic Medicine & Toxicology, KGMU. Different stains having . Medicolegal. importance. Blood. Seminal fluid. Vaginal discharge. Saliva. Faecal. stain. Urine. Dr. Shiuli, Forensic Medicine & Toxicology, KGMU. The success or failure of any criminal investigation often depends on the recognition of physical evidence left at a crime scene and the proper analysis of that evidence.. Crime scenes that involve bloodshed often contain a wealth of information in the form of bloodstains.  The pattern, size, shape, and the location of such stains may be very useful in the reconstruction of the events that occurred. . BIOLOGY & BIOTECHNOLODY DEPARTMENT. In our laboratory, . bacterial morphology . (form and structure) may be examined in two ways:. By observing . living unstained organisms. (. wet mount. ).. 2. By . 5 . Staining . Technique . Practical Of Histopathology. . El-. Hindi.M. . & . Abdelmoneim.A. . . . Objectives: . 1. Understand the . classification of Stains. . . 2. Understand . basic tissue staining methods . Ms. Schultz. The Sam Sheppard Case. On July 4, 1954 Sam Sheppard called police to report that his wife Marilynn was dead in the bedroom. He said the night before, his wife had gone upstairs to bed while he was asleep on the couch. When he went upstairs, he saw his wife covered in blood. He heard a noise and ran downstairs chasing after a 6’3’’ bushy haired man. The two struggled and Dr. Sheppard was choked unconscious. When police arrived, Marilynn was found with 35 wounds to the head and blood drenched the walls, door, and bed. Her face was almost unrecognizable. Sheppard served 10 years in prison before the US Supreme court rules that the trial had been tainted. The evidence was reexamined. Blood spatters and blood drops provided some of the most compelling evidence. Dr. Paul Kirk, an expert in blood analysis, determined the killer could not have been Sam because the attack was perpetrated by a left handed person. Dr. Sheppard was right handed.. .. The presence of color gives the cells significant contrast so are much more visible. . Different stains have different affinities for different organisms, or different parts of . organisms. They are used to differentiate different types of organisms or to view specific parts of organisms. Basic vs. acidic dyes. Differential Stain. Primary stain (stains all cells on slide). Decolorizing step (removes stain from certain types of cells). Counterstain (stains the decolorized cells). Accurately portrays the physical facts. Relates the sequence of events at the scene. Establishes the precise location and relationship of objects and evidence at the scene. Creates a mental picture of the scene for those not present. :. Blood . spatter. patterns can be used to . reconstruct. a crime scene and show how an attack was . made. Blood can connect an . object. with a crime (ex. Discarded . weapon). Blood . can connect a .