Discovery Proteomics Services

Most of our arrays are compatible with any biological fluid. This includes cell culture media, cell lysates, tissue lysates, and all clarified body fluids (serum, plasma, urine, cerebrospinal fluid, BAL, saliva, tears, etc.)

However,the label-based arrays (L-Series), have limited compatibility with lysates and non-serum/plasma body fluids. Our phosphorylation arrays, which detect membrane-bound receptors, are only validated for use with cell and tissue lysates.

In general, any cell-free extract that contains soluble, non-denatured proteins is likely to work with our arrays.

There are a few differences between the glass-slide and membrane-based arrays. The main difference concernsdetection methodology. Our glass-slide based arrays use fluorescence and need a compatible laser scanner. However, our membrane-based arrays use chemiluminescence that is detectable with most western blot imaging systems.

The sample size needed for the glass-slide based is smaller than the membrane-based. Glass-slides require ~70 ul – 100 ul, while the membranes require at least 1 ml, after dilution.

Lastly, the price for the glass-slide based arrays are generally cheaper.

The positive control spots are standardized amounts of biotinylated IgG. They are used for signal normalization, monitoring of the detection step, and to help orient the array image.

The negative control spots are printed with buffer only, and are not expected to give signals. Negative control spots are used for background subtraction.

The areas on the array map labeled as “blank” are empty (there is nothing printed there). Both the negative control and blank spots should give similar intensity values. Either one may be used to represent the background.