Can semen stains glow under black light ?

[nofancies]

Hi all,

Can anyone tell me if semen stains would definitely glow under a black light (UV light) ?

I've been told that they would glow in greenish-yellow under the UV light.
But later on someone said semen stains cannot glow without a substance called 'luminol'.

Which one is true???


And if the semen stains were stuck on a bed sheet like 5 months ago,(being slept on but never been washed), is it possible that the semen substances still remain on it? Would the scrubbing or fiction makes them totally coming off or disappear?

Thanks in advance!

[JohnT]

Need answer fast!

[KneadToKnow]

This thread on a different board starts from the given that semen will fluoresce under black light, and I don't see anyone contradicting that.

[dolphinboy]

Luminol reacts to iron found in blood. Not sure it would work with semen...

[Bear_Nenno]

Luminol is for making blood glow, not semen. Semen will glow on it's own under a black light. Blood does not glow under black light. However, when luminol reacts with the iron in the blood, it glows.

[awldune]

Are we talking about a proper forensic black light, or a black light bulb like you can buy at the supermarket? I have tested with the latter and it didn't work.

[nofancies]

Hi awldune,

is a black light i bought on amazon...I guess that's the supermarket standard.

What's your outcomes?
I have put that stain (on the bed sheet) right on the black light and it appears as yellow. It looks transparent under normal lights.....

[Vinyl Turnip]

I'm curious where all of you experimenters are getting your sample mater.... ohhh. Right.

[JohnT]

This badly-recorded clip from The Office is the first thing I thought of when I read the thread title.

Perhaps the OP is Dwight Schrute?

[KneadToKnow]

Originally Posted by JohnT

This badly-recorded clip from The Office is the first thing I thought of when I read the thread title.

Perhaps the OP is Dwight Schrute?

Funny, I thought of Ming-Na from ER.

[nofancies]

funny clip. :P JohnT.

So now the question becomes: How do semen stains look like after scrubbing off? Would it be transparent? If it is still visible, does it mean it can be tested out?

[friedo]

Originally Posted by JohnT

This badly-recorded clip from The Office is the first thing I thought of when I read the thread title.

I thought of this one.

[drewtwo99]

5 months without washing the sheets. Now THAT'S class!

[KneadToKnow]

Originally Posted by drewtwo99

5 months without washing the sheets. Now THAT'S class!

Without washing the spunky sheets, no less.

[GaryM]

Originally Posted by nofancies

So now the question becomes: How do semen stains look like after scrubbing off? Would it be transparent? If it is still visible, does it mean it can be tested out?

Am I the only one who read this as TASTED out?

[Stink Fish Pot]

Originally Posted by drewtwo99

5 months without washing the sheets. Now THAT'S class!

My freshman year roommate went longer than that.

Needless to say, he wasn't my soph year roommate.

[AaronX]

Originally Posted by awldune

Are we talking about a proper forensic black light, or a black light bulb like you can buy at the supermarket? I have tested with the latter and it didn't work.

Me too. Mine was one of those invisible ink pens, and I suspect the light was more blue than UV. Maybe not much high energy UV.

[nofancies]

I put the uv light very close to the bed sheet, and saw some yellow colour on it. I guess if the room is dark enough and u put the light very close, it works.

[Ambivalid]

Originally Posted by nofancies

And if the semen stains were stuck on a bed sheet like 5 months ago,(being slept on but never been washed)

(bolding mine)


Something tells me that semen was 'summoned' in a solo mission.

[Darth Panda]

Originally Posted by nofancies

How do semen stains look like after scrubbing off?

You spelled rubbing off wrong.

[md2000]

IIRC it was the opening scenes of Basic Instinct (?) where they used the hand-held UV flashlight to show that the dead guy produced and spread a decent amount of seminal fluid all over the bed. The splashes all glow bright white.

Since then, this meme has been used in a lot of Hollywood shows.

I assume this is the concept the OP is asking about.

[Scumpup]

What component of semen, apparently not found in blood, fluoresces?

[Joey P]

Whenever this topic comes up, I always feel the need to point out that laundry detergent also fluoresces under a black light.
I can't say for sure (having never tried it) how much of it holds up after actually being washed but back in college a lot of people would paint their walls (usually graffiti style) with detergent and then during parties they would turn on black lights. The rest of the time you couldn't tell anything was out of the ordinary.

I've often wondered how many of those stains would just be left over laundry detergent residue.

[nofancies]

Would it remain as transparent after being rubbed off?

[KneadToKnow]

Originally Posted by Scumpup

What component of semen, apparently not found in blood, fluoresces?

According to the thread I linked to in post 3, it's phosphorus. I can neither confirm nor deny.

[md2000]

Originally Posted by Joey P

Whenever this topic comes up, I always feel the need to point out that laundry detergent also fluoresces under a black light.

This is the source of the "whiter than white" in old laundry commercials. The detergent would glow in UV (hence in sunlight). Not enough to be noticeable, but enough to add that extra brightness.

In high school we had a play where we used a fairly hefty black light in one sequence (IIRC, about 4 or 8 of the 3-foot flourescent tubes). Not only did fresh white clothing glow in the purplish glow, but so did teeth. Of course this was well before Basic Instinct, so even teenage minds did not make the inappropriate inference. And, I don't recall any unexplained glowing stains either.

[mcgato]

And I thought of this video. Not sure where I first saw it.

[WarmNPrickly]

Originally Posted by Scumpup

What component of semen, apparently not found in blood, fluoresces?

Fluorescence is easily quenched, so it isn't necessary that the fluorescent component is present in semen but not present in blood.

[Darth Panda]

Originally Posted by WarmNPrickly

Fluorescence is easily quenched

Ewwwww.

[Fish Cheer]

Originally Posted by md2000

Not only did fresh white clothing glow in the purplish glow, but so did teeth.

An effect that apparently is hard to reproduce in dentures.