First, As Dottard mentioned, text types (alexandrian, Cæsarean, etc) have largely been abandoned due to the inability to actually prove that that a manuscript was actually from a given text type. For example, Dirk Jongkind states
"Gordon Fee studied the first nine chapters of the Gospel of John and
found that Sinaiticus is a leading witness to the Western text in the
first eight chapters." (Jongkind, scribal habits of Codex
Sinaiticus, p. 25)
So, Sinaiticus, supposedly the an archtype for the so-called Alexandrian text type, here, for 8 chapters, is an archtype for the D-block text. So much for text types.
The only "family" that can actually be spoken of with a limited degree of data is the Majority family (with its various subfamilies.)
Second, it is a common feature of Sinaiticus that the scribe includes larger capital letters (here,ⲉⲓ) with smaller letters scrunched in between (so, here we have ⲈⲒⲥⲦⲟⲛ). For my own part, I wonder if this is due to the scribes' wider letters than the exemplar. That would explain the need to scrunch some letters in. This feature is specific to Sinaiticus. The other 'great' uncials keep the letters at the same height.
However, there are features that are common across all the uncials:
- the nomina sacra. That is that macron (horizontal bar) across the top of ⲑⲥ (θεος).
- the concluding marker (I don't know the name for it). It looks like a nomen sacrum, but it's at the end of a line, usually over a "nu" (ⲛ). It's included for the sake of saving space. So instead of ⲧⲟⲛ, we read ⲧⲟ︥).
The reading then, properly read is:
Third, when there are corrections, they are placed "supralinearly" (above the line of text). So, the corrector adds ⲟⲱⲛ, "who is..." (not ⲑⲱⲛ).
Finally, if you have any interest in these sorts of items, I suggest the following books:
You might have to choose between paying for your kids college tuition or buying these books. But, they, indeed are very valuable reads. As a stop-gap measure, interlibrary loan would be a good choice too.