I came across the term ISHH in my document and discovered that it stands for In Situ Hybridization Histochemistry. I's translating to Russian a document that uses this abbreviation.
Example from the PubMed:
We then validated these findings by using a combination of tools, including the analysis of an additional brain region in an independent subject cohort, cross-validation with an alternate custom microarray platform, and follow-up with in situ hybridization histochemistry (ISHH).
Is there any difference between ISH and ISHH, or are these just synonyms for the same method, in situ hybridization?