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Saliva and saliva spot inspection
钟树荣( PhD ,副教授)昆明医科大学法医学院
Cell Phone : 18213823198 E-mail :
What are the objects found saliva stain easily ?
bite mark
一、 The characteristics of the saliva and saliva stain
• (一)、 saliva
• (saliva) is secretion of the salivary glands, saliva is colorless, tasteless, and is close to neutral liquids.
saliva
无机物质
有机物质
water ( 99.4 %)
Sodium, potassium, chloride, calcium
Phosphoric acid
Carbonic acid
rhodanic acid
Blood type thing
Mucin, ball eggs
Amino acids, urea, urine
淀粉酶麦芽糖酶
• Fall off in addition, the saliva and oral mucosa epithelial cells, a large number of bacteria, a small amount of white blood cells, and food scraps, etc
• Saliva stain is saliva drying after the formation of the spot mark, saliva spot is more common in forensic inspection of one of the biological material inspection
• Saliva spot on a white background with pale yellow, Pale blue fluorescence under ultraviolet light
(二)、 Saliva spot
Confirm the saliva spotConfirm the saliva spot
亲权鉴定亲权鉴定个人识别个人识别(( Individual IdentificationIndividual Identification )) (( parentage testingparentage testing ))
二、 Saliva and saliva spot inspection purpose
Confirm whether or not
Saliva spot
Salivary amylase Check
out the test
三、 Saliva stain proof
Fall out of the oral mucosa
epithelial cells Check out the test
starch Flecked leaching liquid
iodine
The same blue Change the blue
In the spot amylase In the spot amylase
Prove the existence of sugar
theory
(一)、 Saliva amylase detection test
Starch iodine turned blue
碱性铜氯化三苯基四氮唑
Flecked unchanged leaching liquid reaction with starch and iodine blue, can only prove flecked contains amylase, doesn't mean the blackspot is saliva.
matters need attention
(二)、 Fall off oral mucosal epithelial cells of the inspection
cell membrane
nucleus
Cytoplasm
Flat, polygons, the shape is not very regular
Cell membranes are thin, coloring shallow in the cell membrane is the cytoplasm, dyed deep shape larger is the nucleus.
HEDyeing
Acid fuchsin methylene blue staining
attention:
Because saliva spot check material often appear in People's Daily supplies Or items, such as cups, cigarette butts, stone, etc., so confirmed Saliva after the spot, can be directly used to identify the individual, don't have to Species identification.
But when determining the bite of saliva spot, first of all want to make sure Is a person or animal bites.
Determination of saliva secretion spot ABO blood group and the state
Polymorphisms of proteins and enzymes in saliva spot detection
Sex identification of saliva
Saliva of DNA polymorphism analysis (individual identification, paternity test)
四、 Saliva of personal identification
Carrier Type DNArelative amount
About the data
Fresh saliva many 0.8ug/ml
Sterile physiological salt Water gargle water
more 1.5ug/ml
Saliva swabs few 0.26ug/cm2
Saliva spot less 0.16ug/cm2
cigarette end less 12-120ng/ 个
The PCR technology can enlarge the existing DNA is extremely limited to 2 ng, Reason for common saliva (spot) for examination for DNA testing is absolutely Practical and feasible.
The extraction of DNA specimens
1. Biological samples and the
separation of biological
components (carrier)
2. DNA extracted from cells
and cells with other
components
概述
How to obtain nuclear DNA ?
summarize
Nuclear DNA extraction principle
Raw material cells
SDS Heated to boil
nucleus
hypotension
Nuclear membrane rupture, released from within the nuclear DNA
Proteinase
Hydrolysis of DNA binding proteins, DNA free in solution
SDS
Phenol and chloroform, ethanol
Magnetic beads, silica gel
Impurity removal, collecting DNA
概述
( 1 ) Maximum remove the RNA in the sample DNA
solution, the composition such as proteins,
polysaccharides and lipids molecules;
( 2) As far as possible keep the integrity of the extracted
DNA molecules;
( 3) to reduce or eliminate the possible of enzyme
inhibition substances, such as organic solvents,
detergents, metal ions, and dyes, and other enzyme
activity by inhibiting DNA analysis.
The ideal DNA extraction
summarize
五、 Saliva and saliva of extraction
( 1)、 Fresh saliva collection :
First gargle, gauze or cotton swabs to be included in the oral cavity, take out after soaking, dry in ventilation places immediately cool, package equipment inspection, respectively.
If gathering flow of saliva, because it contains blood enzymes, shall be immediately put in boiling water bath (bath boil 10 min) inactivated enzyme type material.
( 2) . Saliva (spot) extract on the site
Found at the scene of the cigarette butts, paper towels, cups, etc should be wearing gloves or with tweezers collection, packaging, respectively.
The scene suspected phlegm article such as stains, skin and bite marks, soaked with saline water gauze wipe patches, transferred to dry patches on the gauze shade, mark
respectively for inspection.
Second step transfer method
• Key to the success of saliva spot transfer :
Drink or jelly contact people in the sales
process, the scene of the mug is not only the criminals used, large area extraction line won't work for sure. This requires inspection case personnel should through the simulation experiment in extraction for examination or normal life habit that target area.
Several kinds of common carrier transfer of saliva
on the spot
With a handle mug
Cup without handle
( 1 ) pouring cup
( 2 ) Mineral water bottle
( 3 ) butt
( 4 ) Jelly shell
0.3 - 0.5cm
( 5 ) bite mark
Generally associated with traces of saliva when occlusion, so it cannot be ignored Wound saliva spot inspection. Found after a bite, use dry first Net gauze to cover, to prevent pollution. Then wipe with two step method Pass the effective components in saliva stain. Do not use hand before inspection Wipe, also don't blot out drugs.
( 6 ) Sunflower seeds
Due to the different people's habits, into hard seeds with shell on the adhesion of the mouth How much cavity epithelium also will be different. But according to the habits of most people , is to use teeth clacking, so it contains relatively few components . Sunflower seeds in the fiber and has strong adsorption, should not be so Should use the method of transfer cells, direct access to the sunflower seeds. In addition, Sunflower seeds on the surface due to contain pigments, add baking in the process of making And have serious effects on amplification so using chelex extracted to The DNA to do further purification and enrichment.
( 7 ) Gum or coffee candy
Summary
Saliva and saliva spot inspection:
• perusal
• Saliva stain proof (amylase, shedding of the oral mucosa epithelial cells)
• DNA polymorphism analysis (individual identification and paternity tests)
• draw