Filtering Nannochloropsis culture

[combra1]

Hello guys,

Is there any way to filter out tetraselmis from a nannochloropsis culture? :idea:
Any ideas on a cheap filter media or any ideas how to get a clean starter culture from this contaminated culture?

I found syringe filters up to 0.45um, and steel mesh filters from 25um, but nothing in the 1-10um range that I could use. Any filter cheaper than 20 bucks would be fine.
(tetraselmis>9um, nannochloropsis<3um)

(I know I could order a clean starter culture, but the question is how could I filter this one)

Cheers

 

[disc1]

We use 5um syringe filters at work all the time. I get them from Fisher, but I am sure there are many more places to get them.

You still may end up with some tetraselmis in your culture though. It only takes a couple of cells getting past the filter.

A better method would be to dilute them and plate them out and then pick the nanno off the plate.

 

[combra1]

Do you mean using agar plate?

 

[billsreef]

Probably easier to do serial dilutions, which is how most all phyto cultures originally got isolated from wild samples. You'll need a bunch of test tubes, 10 should do, that will hold 10ml of culture media. Set the tubes up with your Guillards enriched SW, 10ml worth, and sterilize. After they've cooled, place 1ml of your mixed culture into the first test tube and mix. Then take 1 ml from test tube 1 and place that into test tube 2, mix and repeat by taking 1 ml from test tube 2 and placing into test 3, so and so forth until you get to the last test tube. Seal the tops with some sanitary floss and culture for week under your lights. The last tube in the series with phyto growth should be a pure culture.

 

[disc1]

Do you mean using agar plate?

Yes, mix about 15 - 20g of agar per 1L of your regular growth media to make an agar medium you can grow on. You will probably have to heat it to near boiling to get the agar to dissolve. Then do like Bill said with the serial dilutions. Take 100uL or so of the last few dilutions and plate them out. You should get little patches growing on the plate. ID the one that is nanno and put it back into liquid medium and you have a known pure culture.

The only caveat is light. When growing algae or cyano on a plate, it's best to light it from underneath so you can put the plate right side up (lid down - agar in top half). If the agar medium is nice and clear, you might be able to light from above. If you can't light from underneath and the agar is too dark to light through, then put the plates upside down (lid on top - agar in the bottom part) but you have to be careful that moisture doesn't collect on the agar and wash your culture back together.

 

[combra1]

I will try both and see which one works out better!

Lol I thought there is not a cheap solution to isolate cultures, but both suggested methods look very cheap :fish1:


Cheers!