16S Community Analysis - DIY or Outsource?

Ah, that’s a good point. We should probably do a full costing.
While the AffiGEN kit is more expensive per sample, I’d be tempted to use it first, as it covers everything required to check the DIYNAFLUOR and/or Open Colourimeter Plus in a manner that is less open to experimental error. Then I’d also use it to compare my results with DIYNAFLOUR low-cost protocol. From there, we can be certain of our low-cost results.

A very interesting point - I hadn’t thought about that, but now that I am, I’m wondering if we could expect HOB to be in the top 20 species (I think that’s what the affordable Plasmidsaurus gives) of an environmental soil sample. I’d expect them to be way down the list unless we were sampling them from somewhere that was deficient in other energy sources (like organics).

Unfortunately those organics (humic and fulvic acids, etc.) are likely to contaminate soil samples. My hope is that we can dilute these out sufficiently following an enrichment such that we don’t need the final 16,00 x g filtration step. But I think if you wanted to see how few of our final HOB were in the initial soil sample, you’d need at least the 15,100 x g SciSpin Micro Centrifuge, if not a second hand 16k+ model. And possibly a more expensive 16s service.

I’d like to think that we could get all of this with a UK service if we were offering sufficient samples. I think the key thing with Plasmidsaurus is that they are happy to stack individual samples from multiple customers, and have sufficient throughput to be able to do so.

They still haven’t responded to my enquiry. If they are doing the analysis of our samples in the UK then it may well be that they don’t have sufficient demand to offer all services at the advertised prices and turnarounds. In which case it becomes more than just the issue of international shipping of biological samples. In which case then yes, we’ll need to do our own PCR also.

I thought the AffiGEN kit was pretty much a cheaper alternative to the official Thermo version. As well as the cost advantage, Gemini suggests it’s more convenient in general use as you don’t need serial dilutions for 2 point calibrations. You would however still need serial dilutions for the 6 point validation assay.

Probably best checking this with DIYNAFLUOR. And IO Rodeo, if also trialing the Open Colourimeter Plus. You could produce an excellent paper comparing the 3 reagent sets and two hardware options - better still if you could get a local (or open source proponent) academic with a Qubit involved so you can also compare the industry standard hardware.

I’m afraid Gemini may have gotten a bit confused. The 2-point calibration it refers to is actually from the low-cost assay protocol.

I think it’s pretty clear from DIYNAFLUOR’s build instructions what they did and how they validated it - I wouldn’t know what else to ask them. I also had a look at how IO Rodeo did it before my previous post - they also did serial dilutions using an equivalent to the AffiGEN kit:

The kit includes a 0 ng/µL dsDNA Standard #1 and a 100 ng/µL dsDNA Standard #2. We used these two standards to prepare a dilution series of 20, 40, 60 and 80 ng/µL dsDNA.

Have you had a look at the DIYNAFLUOR preprint? I think they did a great job of comparing reagent sets (HS Qubit, BR Qubit and low-cost) and hardware options (Qubit and DIYNAFLUOR).

Yes, and the AffiGEN kit contains:
1X dsDNA HS Standard #1 (0 ng/µL in TE buffer)
1X dsDNA HS Standard #2 (10 ng/µL in TE buffer)
to conduct those 2-point calibrations - if that’s not exactly what you need beyond the initial setup, then I’m also confused.

The DIYNAFLUOR check I was suggesting was if you wanted to use the lower cost AffiGEN instead of the Thermo chemicals that they used.

No, I haven’t, other than running it through Gemini 2.5 Pro for a summary - which suggested:

They confirm that while the SYBR Safe assay is very cheap (~$0.13 per assay), it is also less sensitive and accurate than the commercial kits. This validates your plan to start with the more reliable AffiGEN kit.

I understand their preprint doesn’t include:
AffiGEN - which is much cheaper than the Qubit reagents used in their build instructions, or
Open Colorimeter Plus - which, though more expensive than DIYNAFLUOR is, to my understanding, a more flexible tool that can be used for much more than just fluorometry.

I can’t seem to find AffiGEN from any local suppliers, and while they mention international shipping on their own website, it seems they don’t ship to the UK?

I was able to find the same kit that IO Rodeo uses from a UK supplier (the same one that seels the QuickDNA kit):

Sorry about that. I assumed that a company advertising prices in GBP would ship to at least one country where that’s the currency. Thinking they might not be happy with my address, I tried two Glasgow universities but they weren’t accepted either. I have contacted AffiGEN support.

The link you gave says “DNA standards are not provided.” It would be great to find a complete kit where all standards, for at least a two point calibration, were given.

OK, this looks much better, both kits have a 0 ng/uL standard. Where they differ is that the AffiGEN kit has a 10 ng/µL second standard whereas the AccuGreen Broad Range Kit has 100 ng/uL. I believe Plasmidsaurus require 10 ng/µL which I was thinking was fortunate as this is the high end of the DIYNAFLUOR 2 point calibration. So, I’d still be more keen on the AffiGEN kit as you’d need to do a 10x diltution of the AccuGreen Broad Range Kit, more than just adding inconvenience, it’s going to reduce accuracy. Is this the one we’re looking for:

AffiGEN’s European distributor appears to be Gentaur Molecular Products, they appear to be lower cost, until they add £45 shipping. If we could get round that, the AffiGEN option would still be better as it requires no dilutions whereas the AccuGreen HS kit still needs you to:

dilute the 20X buffer concentrate to 1X by adding dH2O directly to the bottle containing the concentrated buffer. To 99979-3mL add 57 mL dH2O; to 99979-12.5mL add 237.5 mL dH2O