流式细胞术抗体标记常见问题分析

2010-05-19 14:30 · Eileen

问题 解决方法 无法标记 确保所有的抗体都按照厂商的说明书正确存储。 确保商品化抗体没有超过有效期。 确保已正确加入足量的抗体。 确保抗体已连接荧光素。如果未连接荧光素,需加入连接有荧光素的二抗。 Ensure that secondary antibody is

问题

解决方法

无法标记

确保所有的抗体都按照厂商的说明书正确存储。

确保商品化抗体没有超过有效期。

确保已正确加入足量的抗体。

确保抗体已连接荧光素。如果未连接荧光素,需加入连接有荧光素的二抗。

Ensure that secondary antibody is active – has it been used successfully with other primary antibodies?

Ensure that correct secondary antibody is being used, which will recognize your primary antibody.

If the fluorochrome used is Phycoerythrin or Allophycocyanin based, ensure that the product has not been frozen.

Is the target antigen present on test tissue? Check literature for antigen expression and incorporate a positive control of known antigen expression alongside test material.

Does antibody recognize antigen in test species? Check that antibody cross-reacts with species being used. Not all antibodies will cross-react across species.

Ensure that correct laser is being used to excite fluorochrome, and that correct channel is being used to analyze emissions.

PE抗体无法标记,而FITC抗体的结果却很好

PE conjugate may have been frozen. If so, purchase another vial of antibody.

Paraformaldehyde (PFA) may be a problem. Breakdown of PFA may release methanol, which will affect staining. Make up fresh paraformaldehyde. Cells can be analyzed immediately without fixing.

非特异性染色

Non-specific staining may be due to autofluorescence. Solution: check levels of autofluorescence by including a tube of cells only (i.e. without any antibody) into your panel.

Certain cells express low affinity Fc receptors CD16/CD32, which bind whole antibodies via Fc region. For mouse cells, dilute antibody in SeroBlock FcR.

Non-specific staining may be due to the secondary antibody. Select a secondary antibody that will not cross-react with target tissue.

Ensure that sufficient washing steps have been included.

Titrate test antibody carefully. Non-specific staining may be reduced at lower antibody concentrations.

荧光强度弱

Weak staining may be due to overdilution of antibodies. Ensure that antibodies are used at the correct concentration by titrating antibodies before use.

Weak staining in indirect staining systems may be due to prozoning effect, where highly concentrated antibodies may give weak results. Titrate antibodies carefully.

Weak staining may be due to an excess cell number. Adjust cell population to recommended density.

Weak staining may be due to the antigen expression. Check literature for expected levels of expression.

If antigen expression is weak, select an antibody that is conjugated to a brighter fluorochrome.

Weak staining may be seen if using a cross-reacting antibody rather than one specific for the target species.

Incubation time and temperature with either primary or secondary antibody should be optimized.

侧向角异常

Ensure that cells are used as fresh as possible. Profile may be showing dead cells and debris.

Activation methods may affect scatter characteristics of cells.

If you are using lysing solution, ensure that this is fresh and has been made up correctly.

结果与预期的相反

Some reagents may affect certain antigens and, therefore, may need reviewing e.g. EDTA will affect some platelet markers.

Lysing solutions may affect certain antigens. Select a method that does not interfere with antigen detection.

Some antigens are expressed intracellularly and, therefore, cell permeabilization methods may be required. Check manufacturer’s datasheet for correct permeabilization reagent.

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