Carbohydrate advance

Colloidal iron

Alcian blue-stained (ph 2.5) section reveals very weak staining, and the dye solution needs to be replaced; however no alcian blue is immediately available. A method that could be substituted with almost identical results is

increased staining time in the alcian blue

Microscopic examination of sections stained with alcian blue, pH 2.5, reveals blue stained nuclei. This could be the result of

Ensuring a high content of sugar in mounting medium

Sections stained for amyloid with crystal violet are showing staining bleeding into the surrounding mounting medium. This could be

should have been impregnated longer

On a periodic acid-methenamine silver stain, the tubular basement membranes are stained black, but the glomerular basement membranes show only faintly gray staining. This indicates that the sections:

slides have been cut and stored for a prolonged time

Amyloid control slides are staining very pale with the Congo red method. They have stained satisfactorily in the past. One cause of this problem might be

fixation with glutaraldehyde

Which of the following is the most likely cause of excessive background staining with the PAS?

acidified rinses were not used before and after the colloidal iron

Microscopic review of control sections of small intestine stained with colloidal iron show marked blue staining in the lamina propria. A possible cause is that:

pH of staining solution was too acidic

Review of Congo red stained sections reveals high background staining with the Congo red. One possible cause is:

omitting the oxidizer

It is necessary to determine if there any free aldehyde groups are present in the tissue sections to be stained with the PAS technique. The best method for determining this is to run a section:

carefully preparing a new colloidal iron solution

Microscopic examination of a control section of small intestine stained with colloidal iron shows marked staining of the lamina propria. This could most likely be corrected by

vary the staining time

Microscopic examination of a control section of small intestine stained with alcian blue, pH 2.5, reveals excessive background staining with alcian blue. One possible corrective action for future staining is to

check the Schiff reagent with formaldehyde

Very weak PAS staining is noted on a section of kidney. One problem-solving action that could be tried is to

mucicarmine stock solution was stored at room temperature

Microscopic examination of a control section of small intestine stained with mucicarmine reveals very weak staining in the goblet cells. One possible cause is that the

inadequate oxidation

Microscopic review of a PAS-stained section of kidney reveals a lack of staining of the glomerular basement membrane. Which of the following is the most likely cause of the problem?

ensure that the sections are cut at 8 to 10μm

Polarization of Congo red-stained sections shows only red birefringence. The best corrective action for the future is to:

sections are washed well following Schiff reagent

Microscopic review of PAS-stained sections of kidney reveals very weak staining of the glomerular basement membrane. All of the following are possible corrective actions with the exception of ensuring that the:

should have been impregnated longer

On a periodic acid-methenamine silver stain, the tubular basement membranes are stained black, but the glomerular basement membranes show only faintly gray staining. This indicates that the sections