The easiest way to identify bloodstains

A method of taking pictures of bloodstains at the scene with a multi-band light source.

1. Visual inspection.

The purpose of visual examination is to find blood stains, observe their color, shape and location, so as to prepare and lay the foundation for the next step of the examination, and to help determine the nature of the case and analyze and judge the case.

2. Preparatory test.

This test is a preliminary, tentative bloodstain test to address the possibility of the presence or absence of bloodstains. The preparatory test method is simple and sensitive, but the specificity is poor. A positive result can only prove the possibility of blood stains on the sample, but it cannot be confirmed that it is blood stains.

Of course, a negative result of this test can rule out the possibility of blood stains, and there is no need for the next test.

There are many methods for bloodstain preparation test, the common ones are benzidine test and phenolphthalein.

Trial, aminopyrine test, luminol.

Luminescence test, ultraviolet light.

inspections, etc. 3. Benzidine test.

This test is extremely sensitive and requires only a small amount of sample to be performed. During the test, a small amount of sample was taken, placed on a white filter paper or white magnetic plate, and then glacial acetic acid was dropped sequentially.

Benzidine anhydrous alcohol.

saturated solution and 3 hydrogen peroxide.

One drop each. If there is blood on the sample, an emerald blue reaction occurs, but this reaction can also occur with other substances and is not specific to the bloodstain. Therefore, a positive test can only indicate that there may be blood stains on the sample.

4. Ultraviolet inspection.

Blood stains are earthy brown under ultraviolet radiation, so the use of ultraviolet light can be used to identify the possibility of blood stains.

5. Phenolphthalein test.

As with the benzidine test, the sensitivity of this test is very high. During the test, take a small amount of sample and put it on a white magnetic plate, soak the sample with distilled water, add a drop of reduced phenolphthalein reagent and 3 hydrogen peroxide, if it is bloodstained, it will immediately appear red.

6. Luminol luminescence test.

Prepare the reagent with luminoc, sodium peroxide, plus 100 ml of distilled water. During the test, the prepared reagent is loaded into a glass sprayer, and the sample is sprayed in a dark room or at night. If it is bloodstained, it will show a distinct bluish-white glow.

This reaction is also not specific.

My hospital, no one knows about it.

Summary. Dear, thank you for your patience, the first is to see that the color of the blood stains is dark red, there is a smell of blood, adding benzidine plus glacial acetic acid and hydrogen peroxide will turn blue, alcohol can remove blood stains, FOB test strips to detect whether human blood stains. The second is to smell and smell the smell of blood, if there is a smell of blood, it means blood, on the contrary, if there is a chemical smell, it means dye, I hope it can help you!

If you are satisfied with my service, thank you for giving me a thumbs up with your precious fortune hand.

Dear, thank you for your patience, the first is to see that the color of the blood stains is dark red, there is a bloody smell, add benzidine plus glacial acetic acid and hydrogen oxygen teasing water will turn blue, alcohol can remove blood letters, FOB test strips slip fingers carefully detect whether human bloodstains. The second is to smell and smell the smell of blood, if there is a smell of blood, it means blood, on the contrary, if there is a chemical smell, it means dye, I hope it can help you! If you are satisfied with my service, thank you for giving me a thumbs up with your precious fortune hand.

How can you tell if it's human or animal blood?

Adding benzidine plus glacial acetic acid and hydrogen peroxide will turn blue, alcohol can remove blood stains, and FOB test strips can detect whether there are human blood stains.

Do you buy test strips at pharmacies.

The pro can be bought in large pharmacies.

How does it work? What color does it turn into is human blood?

1.Positive: An orange-red line appeared in the bent burial area and the control area.

The positive results showed that the sample to be tested contained human blood2Negative:

There was no orange-red line in the measurement area, and an orange-red buried ant line appeared in the control area. The negative result showed that no human blood was detected in the sample to be tested.

3.Invalid: No orange-red line appears in the control area.

It should be re-examined.

Restore the test strip to room temperature (20 degrees-30 degrees) before inspection1The sample to be tested is soaked and dissolved in an appropriate amount of distilled water or normal saline, and set aside for 2Tear the sealed pouch open and remove the test strip 3

Insert the sample area of the test strip vertically in the direction of the arrow or dig into the soaking solution of the sample to be tested for 5-10 seconds, and place it horizontally after taking it out. You can also place the test strip horizontally first, and then use a pipette to drop 5-10 drops of the solution (about milliliters) directly into the sample preparation area. 4.

Observe the phenomenon, wait for the orange-red line to appear, and determine the result.

The peroxidase activity of hemoglobin in the blood stains makes the hydrogen peroxide release new ecological oxygen, and oxidizes the colorless benzidine into emerald blue benzidine blue, which is very sensitive, and the blood is diluted to 20-300,000 times, and it is still positive. However, benzidine is not a blood-specific reaction, and because many substances in nature contain peroxidase, it can also cause a positive reaction.

During the test, cut or scrape a small amount of sample material, put it on a filter paper or white magnetic plate, add a drop of benzidine anhydrous alcohol saturated solution, glacial acetic acid, and hydrogen peroxide. When the stain is difficult to remove, the stain can be wiped with distilled water soaked in filter paper to allow the substances on the stain to migrate to the filter paper, and then the test can be performed in the same way.

The color of the blood stains is dark red, there is a bloody smell, adding benzidine plus glacial acetic acid and hydrogen peroxide will turn blue, and the blood stains can be removed with alcohol, and the FOB test strip detects whether it is human bloodstains.

The color of the blood stains is dark red, and if it gets on the clothes, it will be difficult to clean. Next, I will explain to you in detail the easiest way to identify blood stains.

01 Color.

If the color is very bright, it is likely to be dye, not blood, and if it is dark red, it is blood.

02 Smell.

Then smell the smell of blood, if there is a smell of blood, it means blood, if there is a chemical smell, it means dye.

03 Benzidine plus glacial acetic acid plus hydrogen peroxide.

Pour the blood stain into the blood vessel, and then add benzidine plus glacial acetic acid and hydrogen peroxide, if the color is blue, it means that it is bloodstained.

04 FOB test strips.

Then we can use the FOB test strip to determine whether the blood stain is human blood or animal blood, and the result can be obtained in a few minutes.

05 Alcohol.

If it can be washed off with alcohol, it means blood, and if it can't be washed off with alcohol, it means that it is dye.

Hemochromatogen crystallization test Heme chloride crystallization test.

Spectroscopy, precipitation test, species test, benzidine test, phenolphthalein test.

1. The operation of nursing staff is not standardized: First, improper disinfection treatment, the blood collection site needs to be disinfected before blood collection, if blood collection is carried out immediately after disinfection, the alcohol that has not been completely dried may enter the blood vessel with the needle hole, resulting in hemolysis. Second, when collecting blood, it is necessary to choose a suitable needle, because too large a model will lead to too fast blood collection, and a large amount of blood can cause hemolysis and too large blood spots when gushing out rapidly. The needle is too thin and can also cause hemolysis, because the bleeding is not smooth during blood collection, it needs to be squeezed and subjected to a 2

Preventive measures affecting the test results First, standardize the process Breastfeeding as much as possible when collecting blood specimens; Choose the right part;

Summary. Hello glad for you your question is: How to identify blood stains The answer is: color first observe the color of the blood stains, if the color is very bright, it is likely to be dye, not blood, on the contrary, if the color is dark red, it means that it is bloodstains.

Hello, I'm glad for you your question is: How to identify blood stains The answer is: The color first observes the color of the bloodstains, if the color is very bright, it may be a dye, and Li Songhe is not blood, on the contrary, if the color is dark red, it means that it is bloodstains.

If there is a smell of blood, it means blood, and if there is a chemical smell, it means dye. Vertically dismantle the blood stains into the blood vessels with glacial acetic acid and hydrogen peroxide, and then add benzidine plus glacial acetic acid and hydrogen peroxide, if the color is blue, it means that it is bloodstains.

Is this my dried blood?

Not like. Why not.

Why not. I can't see it like blood.