Return records only when all linked records meet criteria

I am trying to write a query that returns all records only when all [Result]
values are 12.0 ?

For example, the query below returns the following sample data:

SELECT tbl_trans.TransNo, tbl_lab.LabNo, tbl_lab.Result
FROM tbl_trans LEFT JOIN tbl_lab ON tbl_trans.Account = tbl_lab.Account
WHERE (((tbl_trans.LabMet)"Y") AND ((tbl_trans.PtType) Not Like "O"))
ORDER BY tbl_trans.TransNo

TransNo LabNo Result
3 4610 9.7
3 1098 9.6
3 1047 8.7
3 875 5.6
5 1303 12.1
5 1214 12.4
5 1094 12.5
8 2176 11.6
8 1415 11.9
8 871 9.6

How do I mofiy the query to return all [TranNo] 5 records only:

TransNo LabNo Result
5 1303 12.1
5 1214 12.4
5 1094 12.5

thanks!