An antibody against a kinase almost never reports activity: the protein level barely moves while the signal does, so what is measured is a phosphorylation, on a stated residue, against the total protein on the same membrane.
A sik1 antibody and the kinases below LKB1
A sik1 antibody reports one of three salt inducible kinases that sit directly below LKB1, and the family shares enough sequence that an isoform specific clone has to be shown not to see the others. Because the kinases are activated by phosphorylation rather than induced, the informative blot is the phospho form beside the total.
A ps6 antibody, and what phosphorylated S6 reports
A ps6 antibody reports ribosomal protein S6 phosphorylated downstream of the growth pathway, which makes it one of the most used readouts of that pathway's state, and the residue matters because different sites respond to different kinases. Serum starvation before stimulation is what makes the signal a response rather than a baseline.
A pip3 antibody and detecting a lipid
A pip3 antibody reports a membrane lipid rather than a protein, which is why detection is hard: the lipid is scarce, short lived and lost by most fixation, so a validated protocol specifies the fixative and the permeabilisation. A domain based probe is often the better reagent, and a phosphatase treated control is the one that shows specificity.
A pkc delta antibody and an isoform in a large family
A pkc delta antibody has to distinguish one isoform from at least ten relatives, so the immunogen region rather than the family name is what decides whether the clone is usable, and a knockdown lysate is the control that proves it. Activation shows as a phosphorylation and as a change in localisation rather than as more protein.
characterization of monoclonal antibodies, and what it covers
The characterization of monoclonal antibodies covers the isotype and the sequence, the affinity and the epitope, specificity against related targets, and behaviour in the intended application, and the last is what most catalogue clones lack. A clone characterised only by an immunogen name is a reagent nobody has tested in the assay it will be used in.
An antibody dilution calculator, and what to use instead
An antibody dilution calculator converts a stock concentration to a working one, which is arithmetic rather than a method: the dilution that works is found by titration in the actual application, since the same clone needs different dilutions on a blot, a section and a flow panel. The calculator is for making the solution, not for choosing the number.
Questions people ask about lkb1 antibody
Does a kinase antibody show activity?
No. Total protein barely moves. Measure a phosphorylation on a stated residue against the total.
How is a dilution chosen?
By titration in the application. The same clone needs different dilutions on a blot, a section and a flow panel.
What proves an isoform specific clone?
A knockdown or knockout lysate, not a peptide competition alone.