Yeast counting

[WBC]

I recently purchased a 1000 X microscope and hemacytometer as I want to be able to count yeast. My problem is that I need to dilute my sample so that there is not so much to count in each square when I have a concentrated sample. I am looking for a measuring pipete to measure out 10 to 1 = 9 parts distilled water to 1 part sample. I only need a maximum of 1 to 2 ML as the diluted sample and it has to be accurate, so I am talking about a very small quantity.

Does anyone else do this sort of thing?

Where can I buy what I need to do this?

 

[scinerd3000]

look up serial dilutions....i used them in microbiology back in the day to do this sort of thing....im looking through my old notes...

 

[scinerd3000]

serial dilution

Serial Dilutions Made Easy


heres the pipette and bulb for cheap:
http://secure.sciencecompany.com/Sibata-Serological-Pipette-10mL-P15991C2616.aspx

 

[Revvy]

Way too cool!!!

So does your phantasmagoric microscope have a camera attachment? If so it would be neat to see pics of those buggers in action...uh, except maybe not during the reproductive phase....We should let them have SOME privacy.

 

[drew91]

I recently purchased a 1000 X microscope and hemacytometer as I want to be able to count yeast. My problem is that I need to dilute my sample so that there is not so much to count in each square when I have a concentrated sample. I am looking for a measuring pipete to measure out 10 to 1 = 9 parts distilled water to 1 part sample. I only need a maximum of 1 to 2 ML as the diluted sample and it has to be accurate, so I am talking about a very small quantity.

Does anyone else do this sort of thing?

Where can I buy what I need to do this?

The easiest thing to do would be to weigh it out (if you have a scale with that kind of resolution). 1mL of water is 1.0g. You can just use an eye dropper or similar.

Disposable Pipettes from MarketLab

Disposable serological pipettes would be slightly pricier, but are still an option.

Pipettes, Serological : Disposable Serological Pipets, Polystyrene, Sterile, Plugged

Otherwise look to score some Gilson/Rainin style micropipettes (a P200 and P1000 combo should suit you well) and disposable tips. You can get them off of ebay, or through places that sell science equipment.

Pipette.com: Gilson Pipetman Traditional Shaft Pipette

 

[Ecnerwal]

Just work with a larger quantity, and then take what you need from that as a sample to count.

ie, rather than fuss with equipping yourself to measure out 1/10 of a mil accurately, take 1 ml and 9 mil and make 10 ml dilute, then take 1 ml of that to count (or to dilute with another 9 ml etc...)

Accuracy in tiny amounts is available, but it's not cheap. 9ml you can do in a 10ml graduated cylinder, 1ml in a graduated eyedropper or a pipette, or you can do it all in the 10ml cylinder, with a non-graduated eyedropper.

 

[WBC]

I just about fell out of my chair when I looked at pipette prices...... WOW!
I think I will use a gram scale as I already have one (by weight).

Thanks for all the replys, you guys are fast.

If anyone has any ideas on yeast farming I am all eyes and ears. I bought a gram stain kit and a blue stain for yeast viability testing too.

I will post pictures as soon as I get a camera adapter. I'm thinking of making one on my lathe.

 

[WBC]

serial dilution

Serial Dilutions Made Easy


heres the pipette and bulb for cheap:
Sibata Serological Pipette, 10mL for sale. Buy from The Science Company.

The above pipete's are well priced and they have a pipete pump for $5.25 too.
Cat. No. - NC-2135
Price - $5.25

 

[scinerd3000]

if your trying to farm- i would pick up some agar powder and Dry malt extract. Heres a more complex recipe if you want to farm on a larger scale:
http://www.condalab.com/pdf/1316.pdf

In my opinion you can get by with just agar, DME and maybe maltose. The challenge is to have selective growth twords only yeast on the plates. The pH of the agar plates should be low in order to inhibit growth of other organisms and therefor you may need other adjunct to drop the pH if your making this from scratch. Your other option is to look into Malt/Wort agars which are pre-made. I will be doing this sometime in the near future as a way to culture proprietary yeast strains from bottles using streak plating.