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How does the single spot map work in SpotMap?

In SpotMap the analysis spots are categorised as present or absent from the image which you are analysing, The colour scheme is based on comparison to the base image and identifies those spots which are Common, Missing or Additional. The video below describes how the spot map is generated and how you can calculate percentage coverage.

What you we mean by single spot map?

Spot outlines or a spot map identifies the location of all spots on the gel and blot images. When a spot is not present on one of the images SpotMap will still produce a spot outline on that image. Spots on each image can then be categorized as Absent and Present in regards to the blot and Additional if there is a spot on the blot image that isn’t visible on the gel image.

Why is a single spot map used for the analysis?

Using one single spot map for all images allows you to correctly identify matching spots and missing spots on the blot. Alignment allows this to happen by correctly matching the spots in same coordinate space on the images.

How is the single spot map generated?

Users should detect spots on the gel first as stained gels are often more defined than a western blot image. The spot outlines are then transferred to the blot (this should be done after alignment as it helps to see where the spots exist on the blot) then you can detect additional spots on the blot. This will give you one single spot map for determining matching and missing spots. Watch the video for more information on how the spot map is generated.

How is coverage determined from the single spot map?

The number of spots categorised as Present, Absent or Additional are used to calculate percentage coverage of each image compared to the base image. Spots absent from both the base image and secondary image for which coverage is calculated are not included in the calculation.

 

Percentage coverage = (Present and Additional) / (Present + Absent + Additional) x 100

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