Hemotaphonomy

The Hämotaphonomie (from the Greek Haima blood , Taphos grave and Nomos natural law ) is the science that deals with the Cytomorphology concerned by blood stains. This term was suggested by the Catalan biologist Policarp Hortolà in the 1990s .

The subject of hemotaphonomy is the cytomorphology of blood cells in samples stained with blood. The method of studying hemotaphonomy is to analyze light-dark images taken with a scanning electron microscope . Recently it has been suggested that confocal microscopy could be a practical alternative to scanning electron microscopy when a very high level of detail of the surface of blood stains is not required. In particular, changes in the appearance and size of the cell components as well as the properties of their cell position and their appearance depending on the superficial topography and composition of the substrate are examined in this type of analysis.

Long before the appearance of the first commercial scanning electron microscope in the middle of the 20th century, the microscopic determination of blood stains was carried out sporadically as a tool for forensics, with the doctor and chemist from Menorca , Mateu Josep Bonaventura Orfila , attempting this first. The applied hemotaphonomy looks for blood stains as criminal or archaeological evidence and should not be confused with the analysis of bloodstain pattern analysis , which deals with the analysis of the color, shape and size of blood stains, but which has been partially refuted by well-known scientists .

Vertebrate blood and mammalian erythrocyte morphology in the body and samples

Vertebrate blood is a suspension of cells in a liquid medium ( plasma ). There are three types of cells in this tissue: erythrocytes (red blood cells), leukocytes (white blood cells), and platelets .

Unlike other vertebrates, mammals have red blood cells without a nucleus . As an exception among the other vertebrates, the salamanders of the Plethodontidae family have a proportion of red blood cells without a nucleus, whereas the species Batrachoseps attenuatus has almost 95% nucleus-free blood cells. The Maurolicus muelleri ( Teleost fish) also has erythrocytes without cell nuclei.

Typical mammalian erythrocytes are biconcave, disc-shaped due to the lack of a cell nucleus . This does not apply to the Camelidae family , in which the red blood cells are oval shaped. Other physiological forms - which occur to a small extent or are pathological - are the echinocytes (cells in the shape of the thorn- apple), dacryocytes (tear-shaped cells), schizocytes (broken cells), keratocytes (antler-shaped cells), spherocytes and sickle cells .

Most of the red blood cells in blood stains have the same morphology as those described in hematology . However, two erythrocyte morphologies can be specifically traced back to blood drying phenomena, so that they can be regarded as characteristic morphologies of blood spots of (at least) mammals and are therefore not in physiological states. According to Hortolà, these forms are:

Moon-shaped cells, called hecatocytes by Hortolà (lunoid forms that are related to the erythrocyte-plasma interaction in the dry state; etymologically by Hecate ).
Negative cells, called Janocytes by Hortolà (negative replicas, based on the print of the dry plasma; etymologically by Janus ).

literature

The aesthetics of haemotaphonomy. Stylistic parallels between a science and literature and the visual arts .

Individual evidence

↑ Haemotaphonomy. Retrieved September 25, 2019 .
↑ Policarp Hortolà: Microscopic imaging of human bloodstains: testing the potential of a confocal laser scanning microscope as an alternative to SEMs . In: Micron . tape 130 , 2020, doi : 10.1016 / j.micron.2019.102821 .
↑ Policarp Hortolà: Human bloodstains on bone artefacts: an SEM intra- and inter-sample comparative study using ratite bird tibiotarsus . In: Micron . tape 90 , September 5, 2016, p. 108–113 , doi : 10.1016 / j.micron.2016.09.002 ( researchgate.net [accessed September 25, 2019]).
↑ Gran enciclopèdia catalana - hemotafonomia
↑ Marziale Milani, Roberta Curia, Claudio Savoia: FIB / SEM Haemotaphonomy: Red Blood Cells Identification in Unprepared Samples of Forensic Interest . Volume 1, No. 1, 2015, pp. 1-8.
^ Solomon Moore: Science Found Wanting in Nation's Crime Labs . In: The New York Times . February 4, 2009, ISSN 0362-4331 ( nytimes.com [accessed September 25, 2019]).
^ Leora Smith: How the Dubious Science of Blood-Spatter Analysis Spread Like a Virus. December 13, 2018, accessed September 25, 2019 .
^ Victor E. Emmel: Studies on the non-nucleated elements of the blood. II. The occurrence and genesis of non-nucleated erythrocytes or erythroblastids in vertebrates other than mammals. In: The American Journal of Anatomy. Volume 33, No. 2, 1924, pp. 347-405. doi : 10.1002 / aja.1000330207 .
↑ Karl Georg Wingstrand: Non-nucleated erythrocytes in a teleostean fish Maurolicus muelleri (Gmelin). In: Journal for Cell Research and Microscopic Anatomy. Volume 45, No. 2, 1956, pp. 195-200. doi : 10.1007 / BF00338830
↑ Policarp Hortolà: Red blood cell haemotaphonomy of experimental human bloodstains on techno-prehistoric lithic raw materials. In: Journal of Archaeological Science. Volume 29, No. 7, 2002, pp. 733-739.

[1] Haemotaphonomy. Retrieved September 25, 2019 .

[2] Policarp Hortolà: Microscopic imaging of human bloodstains: testing the potential of a confocal laser scanning microscope as an alternative to SEMs . In: Micron . tape 130 , 2020, doi : 10.1016 / j.micron.2019.102821 .

[3] Policarp Hortolà: Human bloodstains on bone artefacts: an SEM intra- and inter-sample comparative study using ratite bird tibiotarsus . In: Micron . tape 90 , September 5, 2016, p. 108–113 , doi : 10.1016 / j.micron.2016.09.002 ( researchgate.net [accessed September 25, 2019]).

[4] Gran enciclopèdia catalana - hemotafonomia

[5] Marziale Milani, Roberta Curia, Claudio Savoia: FIB / SEM Haemotaphonomy: Red Blood Cells Identification in Unprepared Samples of Forensic Interest . Volume 1, No. 1, 2015, pp. 1-8.

[6] Solomon Moore: Science Found Wanting in Nation's Crime Labs . In: The New York Times . February 4, 2009, ISSN 0362-4331 ( nytimes.com [accessed September 25, 2019]).

[7] Leora Smith: How the Dubious Science of Blood-Spatter Analysis Spread Like a Virus. December 13, 2018, accessed September 25, 2019 .

[8] Victor E. Emmel: Studies on the non-nucleated elements of the blood. II. The occurrence and genesis of non-nucleated erythrocytes or erythroblastids in vertebrates other than mammals. In: The American Journal of Anatomy. Volume 33, No. 2, 1924, pp. 347-405. doi : 10.1002 / aja.1000330207 .

[9] Karl Georg Wingstrand: Non-nucleated erythrocytes in a teleostean fish Maurolicus muelleri (Gmelin). In: Journal for Cell Research and Microscopic Anatomy. Volume 45, No. 2, 1956, pp. 195-200. doi : 10.1007 / BF00338830

[10] Policarp Hortolà: Red blood cell haemotaphonomy of experimental human bloodstains on techno-prehistoric lithic raw materials. In: Journal of Archaeological Science. Volume 29, No. 7, 2002, pp. 733-739.