Hi Wong Su

1) As per the picture the cells look healthy to me. However have you seen any turbidity in the medium or enhanced acid production which wud be an indicator of bacterial contamination.

2) You have also mentioned the presence of black dots within the cells. may be your cells are displaying vacuolization which is usually not a good sign and indicates some sort of osmotic imbalance in the cells. So How about your PBS as well as media. Are they maintaining the osmolality in the desired range?

3) You got to read these papers may be they will also help I have attached them.

Good Luck!!

Hi Stephanie

- From my point of view what you call mucus are normal cell protrusions (i.e. lamellipodia). They just seem different because they are more flat than the cell body.

- As for the black dots I think Vikrant has a good point there

However, generally, the cell culture does look healthy to me as well.

Hi Stephanie,

I worked with SH-SY5Y cells for several years.

Several authors report the existence of cytoplasmic neurosecretory granula in SH-SY5Y cells, what I suppose can be the black dots you mention.

I'm not sure what you mean by the " mucus like layer ", but I think you are just looking at the more adherent phenotype of SH-SY5Y cells.

I strongly recommend you to read the paper by Kovalevich and Langford on the use of SH-SY5Y cells:

Article Considerations for the Use of SH-SY5Y Neuroblastoma Cells in...

btw from what I can see on your photo your cells look normal SH-SY5Y cells.

good luck on your work!

Hi Wong Su,

I am also working with the same cell line & as you can see in the picture attached here, there are those black dots within the cells. And if you zoom in further you will get to see few cells (center of the pic) having round circular protrusions. However cells are growing well. If you already solved the problem, please give me some input. Thanks.

Joana Fernandes Da Rocha Hello Joana, I looked over the paper and it was very helpful. However, I noticed in the paper that there were two types of cells S and N type cells that were differentiated and they look very similar to the cells that I currently have and I am not trying to differentiate them. Would you happen to know why it happens?

Stephanie Wong Su I'm sorry for my late reply, but I missed your last answer. Are you trying to say that you are not using any standard differentiation factor of these cells (like retinoic acid) but your cells look differentiated anyway?

Both types, S and N, exist even when your don't differentiate the cells. If you are culturing your cells for a long time, I think you can have differences in the proportion of these types depending on how you are culturing the cells, and making cells passages and so on. For example, during my PhD one of our batches of cells seemed to be highly enriched in the N-type (because we were performing cell passages without trypsin for a while), and cells from this batch started to differentiate even without adding specific dif factors (and there was always S-types cells present that would grow in number with time in culture).

Also, do you use cell medium supplemented with serum? serum has a lot of factors, and certainly some of them have the ability to promote dif of cells (even if its not that notorious as retinoic acid).

hope this helps