Matrix Lookup Issue with ISNUMBER & SEARCH

Hi,

I work in a laboratory, and we have various freezers named: Fz1, Fz2, ..... Fz9, Fz10, Fz11, Fz12

We keep various samples in these freezers such as blood.

I have created a large spreadsheet which links each sample type to the freezers which store them. (The table also has more columns with more information I have kept out)
See below a very basic example

Saliva Fr2; Fr6
Urine Fr1
Plasma Fr1; Fr12
Serum Fr8; Fr11; Fr12

I have created another tab with a table of sample types going down the page and freezers going across.
I want the cells to link back to the tab described above, highlighting the cells which show which freezers contain which samples, as shown in the image.
The cells have a formula =ISNUMBER(SEARCH(B$1,Freezer!$A$1)) where Freezer is the other tab containing the table
Freezer example.PNG


However the issue is this says Freezer Fr1 contains Serum which isn't the case.
I understand this is because Fr11 and Fr12 contain "Fr1" in them.
I have tried ways of editing this, however, any solution I have found doesn't work as there are other freezer names in the original cell it's pulling from. I also want to keep the Substring as the cell rather than the text, as we have many freezers.

Administrative Note:

Welcome to the forum.

Members will tailor the solutions they offer to the version (NOT release number) of Office (Excel, NOT Windows) that you have. Please check that your forum profile is up-to-date in this respect. If you aren't sure, in Excel go to File | Account and report what it says below the MS logo at the top of that page. If your version is for Mac, please also state this. Thanks.

There are instructions at the top of the page explaining how to attach your sample workbook.

A good sample workbook has just 10-20 rows of representative data that has been desensitised. It also has expected results mocked up, relevant cells highlighted and a few explanatory notes.

Administrative Note:

We would very much like to help you with your query, however the thread title does not really convey what your request is about. Tell us what you are trying to do, not how you think it should be done.

Please take a moment to amend your thread title. Make sure that the title properly explains your request. Your title should be explicit and not be generic (this includes function names used without an indication of what you are trying to achieve).

Please see Forum Rule #1 about proper thread titles and adjust accordingly. To edit the thread title, open the original post to edit and then click on Go Advanced (bottom right) to access the area where you can edit your title.

(Note: this change is not optional. As yo uare new here, I have done it for you this time.)

@SAMS

I asked you to update your forum profile and to provide a sample workbook. Please would you do both now. Thanks.