The intestinal glands in the colon are often referred to as colonic crypts.
The epithelial inner surface of the colon is punctuated by invaginations, the colonic crypts.
The colon crypts are shaped like microscopic thick-walled test tubes with a central hole down the length of the tube (the crypt lumen).
Four tissue sections are shown here, two (A and B) cut across the long axes of the crypts and two (C and D) cut parallel to the long axes.

In these images the cells have been stained to show a brown-orange color if the cells produce a mitochondrial protein called cytochrome c oxidase subunit I (CCOI or COX-1).
 The nuclei of the cells (located at the outer edges of the cells lining the walls of the crypts) are stained blue-gray with haematoxylin.
As seen in panels C and D, crypts are about 75 to about 110 cells long.
The average crypt circumference is 23 cells.
From the images, an average is shown to be about 1,725 to 2530 cells per colonic crypt.
Another measure was attained giving a range of 1500 to 4900 cells per colonic crypt.
Cells are produced at the crypt base and migrate upward along the crypt axis before being shed into the colonic lumen days later.
 There are 5 to 6 stem cells at the bases of the crypts.

As estimated from the image in panel A, there are about 100 colonic crypts per square millimeter of the colonic epithelium.
 The length of the human colon is, on average 160.5 cm (measured from the bottom of the cecum to the colorectal junction) with a range of 80 cm to 313 cm.
The average inner circumference of the colon is 6.2 cm.
Thus, the inner surface epithelial area of the human colon has an area, on average, of about 995 cm², which includes 9,950,000 (close to 10 million) crypts.

In the four tissue sections shown here, many of the intestinal glands have cells with a mitochondrial DNA mutation in the CCOI gene and appear mostly white, with their main color being the blue-gray staining of the nuclei.
 As seen in panel B, a portion of the stem cells of three crypts appear to have a mutation in CCOI, so that 40% to 50% of the cells arising from those stem cells form a white segment in the cross cut area.

Overall, the percentage of crypts deficient for CCOI is less than 1% before age 40, but then increases linearly with age.
Colonic crypts deficient for CCOI reaches, on average, 18% in women and 23% in men, by 80–84 years of age.

Crypts of the colon can reproduce by fission, as seen in panel C, where a crypt is dividing to form two crypts, and in panel B where at least one crypt appears to be fissioning.
 Most crypts deficient in CCOI are in clusters of crypts (clones of crypts) with two or more CCOI-deficient crypts adjacent to each other (see panel D).
The intestinal glands in the colon are often referred to as colonic crypts. The epithelial inner surface of the colon is punctuated by invaginations, the colonic crypts. The colon crypts are shaped like microscopic thick-walled test tubes with a central hole down the length of the tube (the crypt lumen). Four tissue sections are shown here, two (A and B) cut across the long axes of the crypts and two (C and D) cut parallel to the long axes.
In these images the cells have been stained to show a brown-orange color if the cells produce a mitochondrial protein called cytochrome c oxidase subunit I (CCOI or COX-1).  The nuclei of the cells (located at the outer edges of the cells lining the walls of the crypts) are stained blue-gray with haematoxylin. As seen in panels C and D, crypts are about 75 to about 110 cells long. The average crypt circumference is 23 cells. From the images, an average is shown to be about 1,725 to 2530 cells per colonic crypt. Another measure was attained giving a range of 1500 to 4900 cells per colonic crypt. Cells are produced at the crypt base and migrate upward along the crypt axis before being shed into the colonic lumen days later.  There are 5 to 6 stem cells at the bases of the crypts.
As estimated from the image in panel A, there are about 100 colonic crypts per square millimeter of the colonic epithelium.  The length of the human colon is, on average 160.5 cm (measured from the bottom of the cecum to the colorectal junction) with a range of 80 cm to 313 cm. The average inner circumference of the colon is 6.2 cm. Thus, the inner surface epithelial area of the human colon has an area, on average, of about 995 cm², which includes 9,950,000 (close to 10 million) crypts.
In the four tissue sections shown here, many of the intestinal glands have cells with a mitochondrial DNA mutation in the CCOI gene and appear mostly white, with their main color being the blue-gray staining of the nuclei.  As seen in panel B, a portion of the stem cells of three crypts appear to have a mutation in CCOI, so that 40% to 50% of the cells arising from those stem cells form a white segment in the cross cut area.
Overall, the percentage of crypts deficient for CCOI is less than 1% before age 40, but then increases linearly with age. Colonic crypts deficient for CCOI reaches, on average, 18% in women and 23% in men, by 80–84 years of age.
Crypts of the colon can reproduce by fission, as seen in panel C, where a crypt is dividing to form two crypts, and in panel B where at least one crypt appears to be fissioning.  Most crypts deficient in CCOI are in clusters of crypts (clones of crypts) with two or more CCOI-deficient crypts adjacent to each other (see panel D).
Intestinal gland