Blood stains, detection

Descriptions of methods for the estimation or detection of morphine and/or codeine in urine,213-218 body fluids,219 blood,220 blood stains,221 hair,222 and opium,223 for the examination of illicit heroin,224-226 and for the estimation of dihydromorphinone in plasma227 have been published, the effect of formaldehyde on the estimation of morphine has been examined,228 and a bioassay for morphine and naloxone has been described.229... 

THE need for precise methods of identifying the species of origin of a blood stain or tissue fragment found in an archaeological setting is well documented. In his analysis of stone tools of various types and materials, Loy (1) detected surface blood deposits on 86% of the samples. These artifacts... 

Use Organic synthesis manufacture of dyes, especially of Congo red detection of blood stains stain in microscopy reagent stiffening agent in rubber compounding. 

MAJOR USES Manufacture of azo dyes, plastic films, rubber compounds spray reagent for sugars used for detection of hydrogen cyanide and sulfate detection of blood stains. 

OTHER COMMENTS used in the manufacture of azo dyes used for the detection of hydrogen cyanide, hydrogen sulfate, and blood stains used as a hardener in rubber compounds. 

An ultraviolet light source can be used to detect a blood stain that has been cleaned up. It s also possible to use a chemical substance like luminol or phenolphthalein to detect the presence of hemoglobin, revealing its presence even after the visible stain has been washed away. 

Bauer M, Kraus A, and Patzelt D (1999) Detection of epithelial cells in dried blood stains by tevetse ttan-scriptase-polymerase chain teaction. Journal of Forensic Sciences 44 1232—1236. 

The detective didn t believe him. But two days later police found a blood-stained knife in a trash can two blocks from the crime scene. That weapon was exactly five and a half inches long, one inch wide, and one sixteenth of an inch thick. And the blood on its blade matched... 

Widely used fiuorophore. Finds use in microscopy, as a laser dye in forensics and serology to detect latent blood stains, and in dye tracing. When substituted with reactive groups can be used to covalently label proteins. The excitation maximum (494 nm) is conveniently close to the spectral line of the argon-ion laser (488 nm) which makes fiuorescein an important fiuorophore for confocal scanning laser microscopy [123]. A common donor for FRET applications. 

The latter is the well-known basis for the detection of very small quantities of blood (as in blood-stains) in forensic medicine [24]. Co-(II)-, Cu-(II)-, Cr-(III)-ions have also been determined by the luminol reaction. In addition to highly sensitive photomultipliers, one can also use photographic films for the detection and determination of the chemiluminescence light [25]. 

Detecting the presence of small, even invisible, amounts of blood is routine. Physical characteristics of dried stains give minimal information, however, as dried blood can take on many hues. Many of the chemical tests for the presence of blood rely on the catalytic peroxidase activity of heme (56,57). Minute quantities of blood catalyze oxidation reactions between colorless materials, eg, phenolphthalein, luco malachite green, luminol, etc, to colored or luminescent ones. The oxidant is typically hydrogen peroxide or sodium perborate (see Automated instrumentation,hematology). 

The life span of the normal red blood cell is 120 days this means that slightly less than 1% of the population of red cells (200 billion cells, or 2 million per second) is replaced daily. The new red cells that appear in the circulation still contain ribosomes and elements of the endoplasmic reticulum. The RNA of the ribosomes can be detected by suitable stains (such as cresyl blue), and cells containing it are termed reticulocytes they normally number about 1% of the total red blood cell count. The life span of the red blood cell can be dramatically shortened in a variety of hemolytic anemias. The number of reticulocytes is markedly increased in these conditions, as the bone marrow attempts to compensate for rapid breakdown of red blood cells by increasing the amount of new, young red cells in the circulation. 

Figure 52-3. Diagrammatic representation of the major proteins of the membrane of the human red blood cell separated by SDS-PAGE. The bands detected by staining with Coomassie blue are shown in the two left-hand channels, and the glycoproteins detected by staining with periodic acid-Schiff (PAS) reagent are shown in the right-hand channel. (Reproduced, with permission, from Beck WS, Tepper Ri Hemolytic anemias iii membrane disorders, in Hematology, 5th ed. Beck WS [editor]. The MiT Press, 1991.)...

Glyoxal-based fixatives work faster than formalin. Small biopsies may be ready to process after only an hour while properly grossed larger specimens are ready in about 6h. Structural detail is remarkable in its clarity (Fig. 12.9). Red blood cells are lysed, but that rarely presents a problem. Eosinophilic granules are reduced in prominence (see below). Special stains work well, except for tests for iron (the mildly acidic pH is detrimental) and the silver detection methods for Helicobacter pylori. Most notably, glyoxal-fixed tissues retain strong immunoreactivity for most antigens. The chemistry behind most of this is known. 

Diagnosis Physical findings are non-specific. There is possible widening of the space in the chest between the pleural sacs of the lungs that contain all the viscera of the chest except the lungs and the pleurae which can be detected by a Gram stain of the blood and by a blood culture late in the course of illness. 

This test depends on attaching virus protein to a small laboratory dish. A serum sample is prepared from the blood of the individual to be tested, and it is placed in the dish containing bound HIV viral proteins. If HIV-specific antibodies are present in the serum, they will become tightly bound to the dish by way of the HIV proteins. The serum is then removed, and the dish is washed during this procedure, only antibodies specific for HIV will be retained. The dish is then reacted with a stain that will detect any human antibodies. Thus, dishes that were exposed to serum containing HIV-specific antibodies will be stained, while dishes from antibody-negative serum samples will be unstained. A modified ELISA test was developed in which the virus proteins are attached to small beads that can float in solution, instead of to the bottom of the dish. The test is carried out in a test tube and proceeds as before. 

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