Find only cells containing certain characters or a certain string

[dmp3lic]

I have a list of cells from which I want to identify only those cells containing certain string of characters.

Example:
A1 = 12345AB321
A2 = TROH824433235ge3
A3 =ffewipmnp34525AB
A4 = saswAf7481B
A5 =AB12

so I want to write a formula that returns "True" for all cells that contain the string "AB".
So the results should be A1, A3 and A5
not A4 because AB not together, because A4 is saswAf7481B

 

[Joe4]

Try this:

=ISNUMBER(FIND("AB",A1))