Making Slanted OCT Blocks

Why:  With some cryostats, you NEED to make slanted OCT blocks in order to line up.  (Note that I said “some.”  You never know which cryos require it.  It keeps things exciting.)

If you make a perfectly level block and try to line it up on one of said cryos, you’ll find that it's impossible to close the gap between the top of the block and the blade.  Your options at this point are:

1. Rotate the block upside down. You'll also have to pick up the sections with an upside-down slide so that piece 1 is still on the left side. Or,
2. Melt it down and remake it as a slanted block.

Since you never know which cryos require this, it’s best to just get into the habit of making slanted mounts every single time. 

How:  When sandwiching the tissue between the heat sink and the disc on the cold bar, angle the mounting slide so that the OCT block is thinner on the side closest to the cryostat wall.  It doesn’t need to be steeply slanted, just a subtle slant that you probably won’t be able to see until you take the frozen block off the cold bar.  

Be careful not to make the OCT block so thin on one side that it cuts directly into the disc.  You won’t be able to get any sections from it and you’ll have to melt it down and start over. 

Overview of Cancer Types

Basal Cell Carcinoma

Basal Cell Carcinoma (BCC) is the most common form of skin cancer, with over two million cases being diagnosed every year in the United States alone.  This type of cancer is slow growing and rarely spreads to other parts of the body.  If left untreated, however, it can cause disfigurement by invading and damaging the surrounding nerves and tissues.  Most cases of BCC are caused by cumulative UV exposure but can also occur in areas that are protected from the sun.  

Basal cells line the deepest layer of the epidermis.  They are responsible for producing new skin cells to replace the dead ones that are regularly sloughed off.  With enough UV damage, these cells produce skin cells at an abnormal, uncontrolled rate.

BCCs often look like open sores, red patches, pearly pink growths, or scars.  Since they can take on such a variety of appearances, a biopsy is the only reliable way to make a definitive diagnosis.

Nodular:  The most common type of BCC.  Usually presents as a round, pearly growth with rolled edges that may be pigmented (brown) or have small blood vessels on the surface.

Superficial: A less common form of BCC.  Looks like a crusty red patch with a threadlike waxy border.  Is often mistaken for other skin conditions such as eczema or psoriasis. 

Fibrosing or Sclerotic:  A fairly uncommon type of BCC.  Appears ivory-white, is flat or slightly depressed like a scar, and feels firm to the touch.  Difficult to excise because it is often infiltrative and has indistinct margins.