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**passedpawn** · 10-08-2011, 08:41 PM

Just bought a used scope and a hemocytometer for doing yeast counts and viability measurements. Man is this cool. (eek, I think I see a bacterium... yet another thing to worry about!)

I still have to get some stains to spot the dead ones. I can see the cells easily under 400x. I took this pic with a camera pressed up to the eyepiece. Looks much better with the eyes. I don't know why the lines of the hemocytometer don't show up in the pic... they are plain as day when viewed directly.

These cells are from some very dirty BoPils yeast cake, diluted 10:1. Wyeast 2001.

Seven · 10-08-2011, 09:00 PM

Wow that's pretty cool. Nice!

**Reno_eNVy** · 10-08-2011, 09:41 PM

Luckyyyyyyyy

acuenca · 10-08-2011, 09:48 PM

Is that set up in your home?! I'm a lab rat and am so freaking jealous right now!!! I've thought about ordering a "spare" hemocytometer for the lab for yeast use. As I'm doing starters, I'm thinking man... a nice set of pipets and an easypet.

Where did you get the supplies? Fisher?

**passedpawn** · 10-08-2011, 10:07 PM

Quote:

Originally Posted by acuenca

Is that set up in your home?! I'm a lab rat and am so freaking jealous right now!!! I've thought about ordering a "spare" hemocytometer for the lab for yeast use. As I'm doing starters, I'm thinking man... a nice set of pipets and an easypet.

Where did you get the supplies? Fisher?

I bought the hemocytometer off ebay. Improved Neubaur type, looks great, came with a couple of cover slips. Got scope there too.

Yea, that's my den in my house. Not a lab at all, sort of a mess of odds and ends equipment of various types. I have lots of equipment in my closet that I don't keep out all the time. The counter you see there is something I built onto a built-in hutch bookshelf thing... I've got a pic, maybe I'll post that instead of rambling here.

This scope is a lot of fun to play with. Of course, I'm trying to put bugs under it right now.

acuenca · 10-08-2011, 10:11 PM

When I found out that having a pH meter, a scope, microbiological equipment, and a stir plate were perfectly reasonable items to have for this hobby... I knew I was home

Best... hobby... ever.

COLObrewer · 10-08-2011, 10:31 PM

I want one!!

**passedpawn** · 10-09-2011, 01:35 AM

OK, I'm getting a better idea how to feed sample into the hemocytometer (I've been spelling that wrong for about 2 years!).

The coverslip goes on first, then use pipette to drop sample just outside the slip, and the sample capillaries into the 0.1mm channel between the cover slip and the grid. Here, I took another pic at 400x where you can see some of the grid lines. Each of these small boxes is 0.05mm across (0.0025mm^2). 16 of them make up the actual area you have to count (i.e., in the picture below you see half of the squares I counted).

Count all 16 squares, multiply x 250,000, and you have cells per ml. You also need to multiply by any dilution ratio (this was 25:1). In the example below, I counted 61 cells in the full 16 squares. 61 x 250,000 x 25 = 381.25 million cells per milliliter. Easy peezy. Now to determine how many are alive!

A lot of the tutorials have you continue counting blocks, essentially getting the count in the larger 25 blocks in the middle. Then they multiply by 10,000 instead of 250,000. As long as you understand the dimensions of each block, and know that there are 1000 cubic mm in 1 ml, you'll figure out the math.

**passedpawn** · 10-09-2011, 01:37 AM

FYI, hemocytometer, with coverslip and sample loaded onto grid.

***Yooper*** · 10-09-2011, 01:42 AM

That's awesome! I'm jealous. You geek!