I would like to see the protocol of DNA quantification using TKO 100 fluorometer.
Pictures of project https://imgur.com/a/aCpQIQV I am trying to build a in situ fluorometer sensor with an LED and photodiode. I built two circuits, a transimpedance amplifier (TZA) and a multiple feedback band-pass active filter to filter ambient light. In the photos you can see a circuit schematic, a signal from a cheap oscilloscope, the algae water I used to make that signal, and the experimental setup on a breadboard.
Typical in-situ fluorometry methods position the photodetector and 430 nm LED ninety degrees away from each other. The chlorophyll in the water will fluoresce and the detector should pick up red 670 nm light scattered at that ninety degrees. The photo detector has an optical 670nm bandpass filter on the front of it. The 430 nm LED is pulsed at 1kHz from an arduino digital pin (square wave). I am using the MCP6004 as well as some low precision resistors and capacitors. This is the photodiode-filter combination's datasheet, its hard to find because the manufacturer had it made as a special part I believe. https://docs.wixstatic.com/ugd/f74914_65c6e48b466f4e329466082d9a31dc2e.pdf However, according to the manufacturer it has the same properties as this detector: https://www.marktechopto.com/pdf/products/datasheet/MT03-003.pdf
I calculated the frequency limit to be 11kHz and the frequency 3dB is at about 1592Hz for the trans impedance amplifier. For the multiple feedback band-pass active filter I choose C3 and C2 to be 100nF and then I choose Q to be (1kHz center frequency) /(100 Hz bandwidth) = 10. From there I found R3 to be 80 ohms and R4 to be 32kohm.
When I tested it on the algae water I received a signal with an amplitude of around a quarter of a volt at approximately 1.1kHz. (see attached photo). This signal is the same in the dark or in ambient light. However this sensor is for sea water and there isn't the same amount of algae in normal sea water so I need to increase the gain of the circuit. How do I increase the gain without increasing the ambient light noise? Once again It seems to work fine when there is enough chlorophyll in the sample(both in ambient light or in the dark). This shows me that I have successfully filtered out ambient light. Without a sample(open air) the signal is noisy and around 2kHz to 3kHz I thought that would have been filtered out? Any help is appreciated. Once again I think the problem is probably just adjusting this gain correctly to detect seawater. How can this be done?
Thanks
Hello,
I am lookign for applications for a highly sensitive fluorometer. Supposing the proposed system is able to detect biomolecules (DNA, RNA, Proteins; as long as they are fluorescently labeled) to a detection limit in the lower picogram / microliter range and simultaneously in microliter sized volumes.
It would be great if some of you had ideas where such a technology could be applied or what research area could benefit/be accessed by such highly sensitive measurements.
Thank you for any suggestions!
Im moving, and my nanodrop is staying. I’m thinking about buying a Denovix DS-11-FX+ spectrophotometer+fluorometer combo. Anyone have experience with this vs a nanodrop? Vs a Qubit? Or a recommendation for single vs combined machines for DNA quantification?
A rare funding opportunity lets us purchase a new benchtop fluorometer to complement a chemistry major program at a small college. Any recommendations on desired brands and features? I also welcome thoughts on small fluorometers that quantitate DNA/RNA/protein in microliter sample sizes.
I was wondering if anyone had a lead on getting a fairly inexpensive fluorescence spectrometer - used or otherwise. We've been using another lab's, but it's kind of a pain in the ass since it's TECHNICALLY general use, but it's in the other group's lab...
Does anyone have any leads on something like that?
This is a longshot but I'm really struggling here. I've already contacted Turner's technical support but had to leave a voicemail and they haven't gotten back to me yet. My advisor wants answers, and I'm hoping someone here can help! Please let me know if you think I should be posting this elsewhere.
Tl;dr: I'm writing the SOP and testing a new Trilogy lab fluorometer for our lab for ammonium fluorescence. Following published methods, I should be reading standards between 0-800 raw fluorescence units (RFU), but my standards (when prepared in MilliQ water and then using a standard additions method of a sample) are reading at 18,000 RFU + and going very quickly into "instrument saturation" range. I have no real idea what's wrong, and am hoping someone else has experience with these methods/instrument and can help!
I'm a PhD student studying nitrogen biogeochemistry, and we analyze inorganic N in a variety of water sources - precip, stream water, sewage effluent, atmospheric deposition, and ion exchange resin bags. We've always used the indophenol blue method for NH4 analysis, but our UV-Vis is aging and we were having some really bad QA/QC problems with the method (not unique to our lab, it's a big problem with the indophenol blue method).
Recently my advisor purchased a Trilogy lab fluorometer with the NH4/CDOM snap-in module, on the word of her former student who now has a faculty position and runs a lab elsewhere. He said that the method (Holmes et al. 1999, "A simple and precise method for measuring ammonium in marine and freshwater ecosystems") was so easy that one of his undergrads does the method right from the paper. I found in my lit search that the fluorometric method became increasingly popular, and was very well suited for precise and accurate measurements of NH4 at low concentrations, which sounds pretty perfect.
As the grad student with the best chemistry background, I got charged with doing writing up a SOP and doing the lab tests comparing the fluorescence method to the indophenol blue method. Unless I'm just not nearly as smart as my advisor's former student's undergrad, I found that there were several aspects of the Holmes et al. method that just didn't make sense as written. Their lab was also not following the updated method, Taylor et al. 2007 - "Improving the fluorometric ammonium method: matrix effects, background fluorescence, and standard additions." I decided to test both methods with varying standard curves and samples to se
... keep reading on reddit ➡I don't want to step on anybody's toes here, but the amount of non-dad jokes here in this subreddit really annoys me. First of all, dad jokes CAN be NSFW, it clearly says so in the sub rules. Secondly, it doesn't automatically make it a dad joke if it's from a conversation between you and your child. Most importantly, the jokes that your CHILDREN tell YOU are not dad jokes. The point of a dad joke is that it's so cheesy only a dad who's trying to be funny would make such a joke. That's it. They are stupid plays on words, lame puns and so on. There has to be a clever pun or wordplay for it to be considered a dad joke.
Again, to all the fellow dads, I apologise if I'm sounding too harsh. But I just needed to get it off my chest.
Alot of great jokes get posted here! However just because you have a joke, doesn't mean it's a dad joke.
THIS IS NOT ABOUT NSFW, THIS IS ABOUT LONG JOKES, BLONDE JOKES, SEXUAL JOKES, KNOCK KNOCK JOKES, POLITICAL JOKES, ETC BEING POSTED IN A DAD JOKE SUB
Try telling these sexual jokes that get posted here, to your kid and see how your spouse likes it.. if that goes well, Try telling one of your friends kid about your sex life being like Coca cola, first it was normal, than light and now zero , and see if the parents are OK with you telling their kid the "dad joke"
I'm not even referencing the NSFW, I'm saying Dad jokes are corny, and sometimes painful, not sexual
So check out r/jokes for all types of jokes
r/unclejokes for dirty jokes
r/3amjokes for real weird and alot of OC
r/cleandadjokes If your really sick of seeing not dad jokes in r/dadjokes
Punchline !
Edit: this is not a post about NSFW , This is about jokes, knock knock jokes, blonde jokes, political jokes etc being posted in a dad joke sub
Edit 2: don't touch the thermostat
The doctor says it terminal.
Do your worst!
How the hell am I suppose to know when it’s raining in Sweden?
Ants don’t even have the concept fathers, let alone a good dad joke. Keep r/ants out of my r/dadjokes.
But no, seriously. I understand rule 7 is great to have intelligent discussion, but sometimes it feels like 1 in 10 posts here is someone getting upset about the jokes on this sub. Let the mods deal with it, they regulate the sub.
We told her she can lean on us for support. Although, we are going to have to change her driver's license, her height is going down by a foot. I don't want to go too far out on a limb here but it better not be a hack job.
They were cooked in Greece.
I'm surprised it hasn't decade.
He lost May
Now that I listen to albums, I hardly ever leave the house.
Two muffins are in an oven, one muffin looks at the other and says "is it just me, or is it hot in here?"
Then the other muffin says "AHH, TALKING MUFFIN!!!"
Don't you know a good pun is its own reword?
For context I'm a Refuse Driver (Garbage man) & today I was on food waste. After I'd tipped I was checking the wagon for any defects when I spotted a lone pea balanced on the lifts.
I said "hey look, an escaPEA"
No one near me but it didn't half make me laugh for a good hour or so!
Edit: I can't believe how much this has blown up. Thank you everyone I've had a blast reading through the replies 😂
It really does, I swear!
And now I’m cannelloni
Because she wanted to see the task manager.
And boy are my arms legs.
But that’s comparing apples to oranges
Put it on my bill
Heard they've been doing some shady business.
