Yellow Mold again???

[VanFersen]

Just a more or less short explanation: I bought 3 cakes some months ago not all three in the same month but I bought one over Taobao from a very good seller I also bought a lot of other teas. The second one was a quite expansive cake from one of the six famous mountains. This one was around 110$ and one last one. After just some weeks I noticed only on the broken-up parts something yellow in between. The layer outside and the fresh non touched borders were in perfectly condition.

So I shot some photos and asked some the folks in a German tea community I am in. They told me immediately "Throw it away!!! That's yellow mold - very unhealthy!!!" So after some comments about same reaction I did what they say. So you might guess that after this I was a bit scared off buying a whole cake anymore. So I just ordered a sample or in my case now from a very fresh green Laos Sheng 2014 - 100g. I received the Pu today. But already in the moment I opened the doypack I saw a lot of yellow spores or dust on the sides and after I took a closer look at the big piece of this cake I recognized the same stuff why I through my other Pu's away. But is this really yellow mold? How is that possible I mean how is this possible that just this one kind of Tea is such a sensitive one. And again the outside layer is in perfect condition and the borders too. But the again yellow stuff on the broken-up parts. It was always a very fresh or just 2-4 years old Sheng.

Maybe is this something else? Maybe from natural spores from the flower? Here is a picture of the cake and the parts I was talking about and also the inside of the doypack:

[kyarazen]

find a realtime PCR machine somewhere nearby and use the appropriate primers to find out what the mold is

[Evan Draper]

http://babelcarp.org/babelcarp/babelcar ... ase=jinhua
A toothbrush will get mold off pretty well.

[entropyembrace]

find a realtime PCR machine somewhere nearby and use the appropriate primers to find out what the mold is

you don't need realtime PCR for that, it would be a huge waste of money on fluorescent labels that you don't need. Just use basic PCR

[apache]

find a realtime PCR machine somewhere nearby and use the appropriate primers to find out what the mold is

you don't need realtime PCR for that, it would be a huge waste of money on fluorescent labels that you don't need. Just use basic PCR

How about RFLP? This might give you information about different strains as well.

[entropyembrace]

find a realtime PCR machine somewhere nearby and use the appropriate primers to find out what the mold is

you don't need realtime PCR for that, it would be a huge waste of money on fluorescent labels that you don't need. Just use basic PCR

How about RFLP? This might give you information about different strains as well.

PCR is better RFLP is a quick and easy way to tell apart samples that you already know are closely related.

With PCR you can do a series of reactions going down a classification tree starting with the general question "Is it a fungus?" and ending with exactly what strain it is if you want. It probably wouldn't even be expensive if you found a lab that does that sort of thing routinely since they'd have most of the primers already. They're not expensive but you do have to pay shipping for them.

[apache]

find a realtime PCR machine somewhere nearby and use the appropriate primers to find out what the mold is

you don't need realtime PCR for that, it would be a huge waste of money on fluorescent labels that you don't need. Just use basic PCR

How about RFLP? This might give you information about different strains as well.

PCR is better RFLP is a quick and easy way to tell apart samples that you already know are closely related.

With PCR you can do a series of reactions going down a classification tree starting with the general question "Is it a fungus?" and ending with exactly what strain it is if you want. It probably wouldn't even be expensive if you found a lab that does that sort of thing routinely since they'd have most of the primers already. They're not expensive but you do have to pay shipping for them.

When you do PCRs, do you just check possible markers? You would need 2 primers per markers and I don't know how many markers are needed to give a correct identification. Then you might have more than one species and to determine the proportion of each species population, you might need to do real time PCRs.

[VanFersen]

I hoped to receive some serious opinions about what you think it is and not only some talking about PCR or what ever. I would definitely not go to a labor and test it because it would cost more than this sample did. So I was just hoping to see what you think. Is it mold or is it just some part of some yellowish tips (flower parts)?

[kyarazen]

I hoped to receive some serious opinions about what you think it is and not only some talking about PCR or what ever. I would definitely not go to a labor and test it because it would cost more than this sample did. So I was just hoping to see what you think. Is it mold or is it just some part of some yellowish tips (flower parts)?

not flower parts, but I'm dead serious about PCR. if you have a friend working/running a lab that has a machine, or some nearby research/teaching institute it is worth a try.

anyone can speculate on the mold's identity, perhaps you might want to do some microscopy on how the mycelia's shaped, the mold's morphology, it may give you some indication on whether its eurotium or aspergillus

its usually not about the cost of the sample but the value of the knowledge.

[kyarazen]

try : http://www.epa.gov/microbes/moldtech.htm

since you're not using the primers for commercial reasons there's no patent infringement

Eurotium (Aspergillus) amstelodami/chevalieri/herbariorum/rubrum/repens (assay name: Eamst)
Forward Primer EamstF1: 5'-GTGGCGGCACCATGTCT
Reverse Primer EamstR1: 5'-CTGGTTAAAAAGATTGGTTGCGA
Probe EamstP1: 5'-CAGCTGGACCTACGGGAGCGGG


Universal Penicillium, Aspergillus and Paecilomyces varioti (assay name: PenAsp1mgb)
Forward Primer PenAspF1: 5'-CGGAAGGATCATTACTGAGTG
Reverse Primer PenAspR1: 5'-GCCCGCCGAAGCAAC
Probe* PenAspP1mgb: 5'-CCAACCTCCCACCCGTG

and many more..

i regularly order primers from idtdna which is rather inexpensive but you might want to consider a cheap nearby source. there's not so much difference in the quality of primers made in china versus anywhere else in the world now...

[entropyembrace]

To answer your question in more the way you expected :

I don't think it's pollen, I don't see any flowers in the pictures.

It looks an awful lot like Jin Hua (Erotium cristatum) used to make Fuzhuan tea, which is a black tea which is intentionally inoculated with yellow mold. You should probably ask the seller if it's meant to be Fuzhuan and not puerh or if it was stored next to Fuzhuan. Or otherwise ask what is this yellow stuff in my tea to the seller

If it is the mold used to make Fuzhuan then it's not harmful to drink it.

Still if you really gotta know exactly what it is: PCR

[chrl42]

Yellow molds shouldn't appear massively on earlier Heicha, it should be naturally occur.

I see lots of yellow molds on cheap Heicha on the market these days, on which the chemicals have done.

[entropyembrace]

Yellow molds shouldn't appear massively on earlier Heicha, it should be naturally occur.

I see lots of yellow molds on cheap Heicha on the market these days, on which the chemicals have done.

Are they being intentionally inoculated with large doses of spores to produce lots of fungus quickly?

[chrl42]

Yellow molds shouldn't appear massively on earlier Heicha, it should be naturally occur.

I see lots of yellow molds on cheap Heicha on the market these days, on which the chemicals have done.

Are they being intentionally inoculated with large doses of spores to produce lots of fungus quickly?

I don't know what exactly they use.

But from what I know, they DO use chemicals intentionally for the yellow molds.

[apache]

try : http://www.epa.gov/microbes/moldtech.htm

since you're not using the primers for commercial reasons there's no patent infringement

Eurotium (Aspergillus) amstelodami/chevalieri/herbariorum/rubrum/repens (assay name: Eamst)
Forward Primer EamstF1: 5'-GTGGCGGCACCATGTCT
Reverse Primer EamstR1: 5'-CTGGTTAAAAAGATTGGTTGCGA
Probe EamstP1: 5'-CAGCTGGACCTACGGGAGCGGG


Universal Penicillium, Aspergillus and Paecilomyces varioti (assay name: PenAsp1mgb)
Forward Primer PenAspF1: 5'-CGGAAGGATCATTACTGAGTG
Reverse Primer PenAspR1: 5'-GCCCGCCGAAGCAAC
Probe* PenAspP1mgb: 5'-CCAACCTCCCACCCGTG

and many more..

i regularly order primers from idtdna which is rather inexpensive but you might want to consider a cheap nearby source. there's not so much difference in the quality of primers made in china versus anywhere else in the world now...

He still need thermal cycles and reagent mix protocols informations. Also what are the expected PCR products lengths?