Exalpha Biologicals, Inc.

Accelerating the Pace of Discovery

Product Highlight

FIX&PERM Cell Fixation and Permeabilization Kit

Flow cytometric analyses with monoclonal antibodies were so far mainly restricted to cell surface molecules. Intracellular structures such as cytoplasmic or nuclear enzymes, oncoproteins, cytokines, immunoglobulins etc. were largely excluded from such studies. Also excluded from flow cytometric studies were cytoplasmic localizations of well-established membrane molecules like CD3 and CD22, which, in their cytoplasmic form, are the most reliable lineage markers in undifferentiated leukemia. With the FIX&PERM® Kit flow cytometric analysis of intracellular antigens has become as easy as surface antigen studies. The only prerequisite is the availability of suitable antibody conjugates. Most of the available monoclonal antibody conjugates can be used with the FIX&PERM® Kit, some determinants are sensitive, however, to the fixation step involved. This and the optimal fixation time have to be tested for each reagent.

News

Two more of our excellent products have been published by PubMed:

Potential actionable targets in appendiceal cancer detected by immunohistochemistry, fluorescent in situ hybridization, and mutational analysis
Using Exalpha SPARC Antibody (Cat. No. X1867P)

Molecular mechanism underlying the pharmacological interactions of the protein kinase C-β inhibitor enzastaurin and erlotinib in non-small cell lung cancer cells
Using Exalpha's FITC labeled anti PY20 Antibody (Cat. No. X1017)

Proliferation & Apoptosis Assays

Evaluation of cell cycle progression is essential for investigations in many scientific fields. Measurement of [3H] thymidine incorporation as cells enter S phase has long been the traditional method for the detection of cell proliferation. Subsequent quantification of [3H] thymidine is performed by scintillation counting or autoradiography. This technology is slow, labor intensive and has several limitations including the handling and disposal of radioisotopes and the necessity of expensive equipment.

A well-established alternative to [3H] thymidine uptake has been demonstrated by numerous investigators. In these methods bromodeoxyuridine (BrdU), a thymidine analog replaces [3H] thymidine. BrdU is incorporated into newly synthesized DNA strands of actively proliferating cells. Following partial denaturation of double stranded DNA, BrdU is detected immunochemically allowing the assessment of the population of cells, which are actively synthesizing DNA.

Apoptosis, also known as programmed cell death or ankoikis, leads to the elimination of cells without releasing harmful substances into the surrounding area. Apoptosis is the result of a cascade of molecular and biochemical events involving endogenous endonucleases that cleave DNA into the prototypical ‘ladder of DNA fragments’. In addition to producing classical DNA ladders, the apoptotic endonucleases generate free 3’-OH groups at the ends of these DNA fragments to allow for the detection of apoptotic cells using a molecular biology-based, end-labeling technique.