Is this what you mean ?
From a calvinist website Got Questions.
The Calvinistic doctrine of original sin states that Adam’s sin has resulted not only in our having a sin nature, but also in our incurring guilt before God for which we deserve punishment. Being conceived with original sin upon us (
Psalm 51:5) results in our inheriting a sin nature so wicked that
Jeremiah 17:9 describes the human heart as “deceitful above all things and beyond cure.” Not only was Adam found guilty because he sinned, but his sin was imputed to us, making us guilty and deserving of his punishment (death) as well (
Romans 5:12,
19). There are two views as to why Adam’s sin should be imputed to us. The first view states that the human race was within Adam in seed form; thus, when Adam sinned, we sinned in him. This is similar to the biblical teaching that Levi (a descendant of Abraham) paid tithes to Melchizedek in Abraham (
Genesis 14:20;
Hebrews 7:4–9), even though Levi was not born until hundreds of years later. The other main view is that Adam served as our representative, and so, when he sinned, we were found guilty as well.