Arraymold Tissue Microarrayer

For Constructing Both Paraffin and Frozen Tissue Microarrays


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Tips & Tricks For Preparing Tissue Microarrays Using Arraymold




#1. Always punch a paraffin TMA block at room temperature. Cold paraffin can crack when inserting core samples.


#2. Never push the dermal needle into a TMA block. This will damage the TMA block.


#3. When constructing frozen arrays, NEVER snap frozen the arraymold in liquid nitrogen or other snap freezing chemicals. NEVER allow arraymold temperature go lower than -30 ºC


#4. Make a practice TMA block first to test your skills.  And it is a good idea to practice cutting on a test TMA block before you attempt to cut the real one.


Preparing Arrayblock for Cutting


These simple steps will help you set the punches in your paraffin Arrayblock and create a flat surface for cutting.


1st - Once punching is complete, set the block on an uncharged slide (face down) in an oven @ 37 C overnight.  In the morning, the block should be tacky and possibly stuck to slide.  DO NOT PULL SLIDE AND ARRAYBLOCK APART.


2nd – With Arrayblock still warm and tacky, heat another slide in an oven to around 70 c for approximately 10 minutes. Take this separate HOT slide and place under slide stuck to Arrayblock. The Arrayblock surface should turn to liquid quickly. Move the two slides around on the Arrayblock to push any surface air bubbles away and to flatten Arrayblock surface.


3rd – Remove second slide and place Arrayblock with original slide (slide down) on a room temperature counter top for 10 minutes to cool. Once Arrayblock is room temperature, place Arrayblock and slide on an ice tray (No Water) to cool for 20 minutes. Slide should remove easily from Arrayblock and it should now be ready to cut.


Frequently Asked Questions (FAQs)


Q. How should I store the Arraymold when it is not in use?

A. One of the unique benefits of the Arraymold is its size.  It doesn't take up counter space when not in use.  It is best to store the Arraymold in a dark dry place.  When not in use keep the Arraymold in its box in a drawer away from chemicals and light.


Q. If I don't need the full 60 cores how do I make an array without all the extra holes?

A. Just fill the extra holes in the paraffin array block with blank paraffin cores.  This way you can customize the Arraymold to whatever size you need.


Q. What is the depth of the Arraymold cores?

A. The 2mm 60 core Arraymold is 7cm.  The 1.5mm 150 core is 4cm.  The reason why the 1.5mm depth is not as deep as the 2mm is because during our testing we found that the cores rods are stronger and last longer being shorter since they are much thinner than the 2mm core rods.


Q. What is the best way to judge the core depth for creating paraffin array using the Arraymold?

A. If you need to judge your depth, the best way would be to take a Sharpe marking pen and mark the needle to the maximum depth and stay within this distance.  This is especially important when punching with the 1.5mm Arraymold needle.


Q. After repeated use a few of the rubber rods in the Arraymold have broke off.  Is it still possible to still use it?

A. Yes, but you will now have a blank spot in your paraffin array or cryo-array where the punch rods are missing.  Remember; be gentle when pulling the paraffin array or cryo-array block out of the array mold.  Working patient, slow and gentle is the best way to keep the Arraymold rods intact for many molding.


Q. My Arraymold has cracked or split.  Do I need to order another kit or is it possible to continue using it?

A. Yes, you can still use it.  Our tester said even after the Arraymold split they were able to continue making arrays.  Use a rubber band or tape to keep the Arraymold together when you pour paraffin or frozen embedding medium into the Arraymold.  Be gentle when pulling the embedding medium out of the Arraymold.


Q. How cold can I make the Arraymold before it brakes?

A.  We have taken the Arraymold down to -80 Celsius.  The Arraymold was ridged but didn't crack.  Once it thawed to around -30 Celsius it was flexible again.  The Arraymold is designed to use in a cryostat as well as for paraffin molding.  Between -10 to -30 Celsius is the recommend limit for frozen array construction. NEVER snap frozen the arraymold in liquid nitrogen or other snap freezing chemicals. NEVER allow arraymold temperature go lower than -30 ºC


Q. How many paraffin arrays have technicians been able to produce from a single Arraymold before it became unusable?

A. Again the number of uses depends on the technician and how well the Arraymold is treated.  Some labs have been able to create up to 40 molds from one Arraymold.  If you take care of your Arraymold it has the potential of giving you many arrays.


Q. I had difficulty pushing the stylet into the disposable dermal needle.  What is the best way to insert the stylet into the dermal needle?

A.  Before you use the needle gently push and twist the stylet down the needle before you begin an array.  You may notice some plastic coming out of the dermal needle as the stylet goes through it.  This is just left over plastic from when the metal needle part was pressed into the plastic handle.  Once the stylet is through the needle, push it in and out several.  Now you are ready to punch and insert cores.


Q. What paraffin do you recommend for paraffin array construction?

A. We recommend the paraffin you are used to sectioning on a microtome.  It should be embedding type paraffin.  We have not found any benefit to using a specific type of paraffin.  It is the histologist's preference.


Q. Is there a specific type of cryostat embedding medium you recommend for frozen arrays?

A. The best thing we would recommend is to experiment.  Create a frozen array first using hotdog samples and test the embedding medium in your lab.  As we hear from technicians we will try to update this section.


Q. When I was cutting my Cryoarray the punches became loose.  What can I do to eliminate this problem?

A. The punches need to be set into the embedding medium compound.  This is done by melting the surface of the cryoarray block on a metal plate, and then freeze it again before sectioning it in a cryostat.  This step may need to be done several times to the cryoarray as you go deeper into the block.  For further clarification review the instructional video to understand this process step by step.


As more questions are brought to our attention we will add them to this Q&A page.

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