[BioC] splitting clusters and cluster significance

[Subramanian Karthikeyan]

Hi All:

I am clustering ~500 genes using hclust of R.  Visualizing cluster
membership in the dendrogram becomes impossible with so many genes in each
cluster. with all the labels overlapping..Is there a way of printing the
dendrogram on multiple pages so that I can clearly see what is in each
cluster? Or is there a way of splitting the tree so that I see what is in
each cluster....?

Again, how would I test the significance of clustering...i mean a measure
of telling how tight my clusters are, and how separated they are from each
other.

Thanks in advance.

Karthi.