Does Sperm Show Up Under Black Light After Washing

People say that you should never bring black light devices to a Vegas hotel room. Although the reason for it is self-explanatory, there might be more to the story than meets the eyes. After all, black light does not detect only sperm. This means that the spots may be something else other than sperm.

Now, many people say that to get rid of possible sperm spots, all you have to do is to wash the clothes. That raises the question, does sperm show up under black light after washing? The answer is yes. Although it might help reduce it, the stains will continue to be detected under blacklight. Not only that, even the detergent can give you spots on your clothes under a black light so you might have a false positive. The only way to get rid of the spots is by washing it with hydrogen peroxide and lemon.

When it comes to detecting bodily fluids, using a UV light source is a great method. The problem is that it doesn’t give you a conclusive answer about what you’re looking at. There are different substances that react to black light so you might have a saliva stain instead of sperm.

Still, forensic experts still use black light because it’s faster and you don’t have to touch the material in order to know it’s there. Imagine if people had to touch the stain to makes sure is come or just sweat.

Wash With Hydrogen Peroxide And Lemon

There are only a few ways to actually clean up your clothes or any fabric to make sure that it doesn’t show up under black light. Otherwise, it will be cleaned for you, but it will still be visible under black light.

So, the best way is to use hydrogen peroxide and lemon. If you use detergent or soap, you’re still going to get spots but from the detergent and not the come. To the untrained person, it will still be discharge spots.

All you have to do is to use hydrogen peroxide with lemon in a proportion of 3 to 1. Let it soak for 15 minutes, and then wash it normally to get rid of the smell of the hydrogen peroxide.

The Glowing Spot Might Not Be Come

Now, what many people don’t know is that come isn’t the only substance that can show up under black light. This is important to point out because if you use a black light in any room, there are likely many glowing spots to show up. Even though it won’t be sexual discharge, you won’t know.

Pretty much all the bodily fluids and organic residues can show up under black light. Also, there are some chemical substances that can create a spot as well. This means that you might be looking at something else other than come.

To make sure, you might want to use your own portable UV blacklight. One I highly recommend is the Zoomable 395nm Ultraviolet Blacklight DetectorIt has two beam settings for appropriate focus. It is also waterproof and shatterproof. Click Here to get the latest on this great blacklight.

Laundry Detergent

Imagine that you wash your pants. Then a friend gets their black light source that they bought online and point at you. Something is going to glow and people will assume the worst. Now, the truth is that it can be just the detergent residues that you used to clean up your jeans.

Laundry detergents have phosphor added to their formula so the clothes will look brighter under the sun. For this same reason, your clothes will also glow under UV light. This means that all those spots might be just the results of an ineffective rinse process. Even if you do make sure that there isn’t laundry detergent residue, it might still glow.

Blood Only With Luminol

It may come as a shocker, but blood alone does not glow in the dark. The truth is that blood, unlike other bodily fluids, does not have fluorescent properties that will make it glow under black light. So, all those scenes that you’ve watched on crime shows are false.

Now, there’s a way to detect blood in a room. Thanks to science, you can use chemicals that make objects fluoresce like luminol. All you have to do is spray them, and the blood stains will glow.

So, in other situations, besides a crime scene, if you put clothes or objects under black light, it will not glow if the stain is a blood one.


Saliva is another bodily fluid that glows in the dark. The reason for that, or any other substance that glow under black light, is that they have one or more properties that react to the UV light.

So, next time that you’re in a hotel room and you put a pillow under a black light source, freaking out might be unnecessary. The truth is that if you’re in a hotel room, it’s never a good idea to use a black light. You’ll find what you don’t want to. 

Food Only If Edible Fungi

With the exception of all edible fungi, food does not usually glow under black light. There are some exceptions, especially with the latest technological advancements. There are substances that are used to make certain foods like bananas glow under black light.

In normal circumstances, the spots you’ll be seeing glow are not food. They’re likely the bodily fluids that you’re reading here. Still, as you’ll also learn, you’ll need more steps in order to identify what you’re spotting.


The main reason that urine glows under black light is that it contains phosphorus. Cat urine, in particular, glows really bright under black light. So, if you use a black light source in a room, you might not be able to identify through just looking or smelling the spots to what animal the urine belongs to.

Urine also contains other proteins that may be the culprit that makes it glow. Now, unlike sperm, it is easier to clean urine to the point that it doesn’t show up under black light.

Why Come Glows The Brightest

The reason come tends to glow brighter under black light than all the other substances is due to its chemical formation. All the chemical substances that form fluid make it react stronger to the black light.

This means that when the come absorbs the light, it reemits it brighter. Unlike urine, which tends to not glow as bright, man juice shows up stronger under black light. This is helpful when you’re trying to determine what you’re looking at.

For instance, the quantity of Flavin and Choline conjugated proteins that are fluorescent under a black light are high in most come. Still, depending on the heat, time that is there, and other factors the come might not even glow. To determine whether your sample still has bodily fluids, using the Zoomable 395nm Ultraviolet Blacklight Detector will give you an undeniable result. To find out the latest pricing,  Click Here now. 

Chemical Tests Are Still Necessary

If you use black light anywhere in the world, chances are that you’re going to find many glowing spots. The reason behind that is that not everything that glows in this scenario is man juice. As shown above, there are other substances that can glow in the dark.

For that reason, other chemical tests are necessary. It’s common to find spots under black light and turn out to be detergent or just saliva. There are other ways to find out if it really is your man’s load but they might not be pleasant.

Test For PAP

The most obvious way to find out is to touch it. Male sexual fluid will often make the fabric crunching. It leaves a crusty residue all over it. So, the best that you can do is to touch it if you’re brave enough.

The other method, the one that is used by forensic scientists, is to test for prostatic acid phosphatase that is an enzyme that is more common in come than in other bodily fluids.

Final Thoughts

So, this is it. All you needed to know. So, you don’t necessarily need to freak out if you do use a black light in a room and see a bunch of spots. It can be something else.

Now, if you are in a situation where you need to get rid of those spots make sure to follow the process described above. It’s one of the few that actually work. Besides, if you try to wash it in a more traditional manner, meaning with detergent or soap, you can create more spots of something else. So, make sure to wash and rinse well, and you won’t have problems.

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