FISH probe analysis help

[arwen21]

Hi

I am trying to determine if my FISH probe for a gene worked or not. This is my very first time dealing with the analysis of FISH and i am having a little issue determining it. 

I performed FISH on rat lymphocyte culture with custom made FISH probe for gene of interest which is mouse transgene incorporated into rat genome. I want to know if the rat line is homozygous or hemizygous for this particular gene. My understanding is that mouse transgene is almost identical to comparable gene in rat so I should see four dots for FISH staining if the line is homozygous and three dots for FISH staining if the line is hemizygous (Please correct me if you think something else).

1. I want to know how many cells should be analyzed to determine this. 

2. Also i am attaching couple of images to get your opinion about quality of FISH staining. 

I very much appreciate your help and thank you in advance. 

Regards,

Anagha