Renal Pathology Identifying Glomeruli

Identifying Glomeruli

Some Simple Rules:

1) Do not let the tissue dry out as this can happen in seconds.
2) Do not pick up tissue with forceps. Tooth picks are ideal
3) Even if wrapped in saline, please process the tissue as soon as possible. If the tissue has to sit due to some emergency put in the refrigerator immediately. Even if in the refrigerator process within half an hour.

How to maximize your success in identifying glomeruli.
Place the tissue core on a glass slide and view with an ordinary microscope with 4X and if necessary 10X objectives. Avoid use of dissecting microscope (my experience with them has been less than adequate). Glomeruli will be seen as in figure below. One can also easily identify connective tissue and medulla.

If able to confidently identify glomeruli as described above, one 3mm piece for IF and one 1mm piece for EM is all that is required for tissue adequacy. If using the "blind technique" more tissue will be needed obviously.

Distribution of Specimen for Light Microscopy (LM), Electron Microscopy (EM) and Immunofluorescence (IF) using "blind technique"

Two cores of tissue

a. Light Microscopy (LM):

Place one core of kidney in a prepared vial of 10% buffered formalin.
Label with patient name and date.
For a two core protocol, place the larger core in formalin.

b. Immunofluorescent (IF) Specimen:

Place the remaining core in Michel's fixative for Immunofluorescent studies.
Label with patient name and date

c. Electron Microscopy:

We will harvest tissue for EM ourselves from the LM core sent. You do not have to worry about this as we do EM on tissue fixed in formalin.

One core samples:
If difficulties are encountered in obtaining biopsy such that only one core can be obtained, it is still desirable to put a small piece (2-3mm) for immunofluorescence in Michel’s solution. Talk to the local nephrologist or call Ramesh Nair, M.D., to decide how best to triage the tissue based on clinical information (Telphone: 319-356-7000, #1488).