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PathScan® Sandwich ELISA Kit

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13819C 1 Kit (96 assays)

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REACTIVITY
H
Product Includes Volume Solution Color
CD44 Ab Coated Microwells 96 tests
CD44 Mouse Detection mAb (Biotinylated) 1 Ea Green (Lyophilized)
HRP-Linked Streptavidin (ELISA Formulated) 1 Ea Red (Lyophilized)
Detection Antibody Diluent 11 ml Green
HRP Diluent 11 ml Red
TMB Substrate 7004 11 ml Colorless
STOP Solution 7002 11 ml Colorless
ELISA Wash Buffer (20X) 25 ml Colorless
ELISA Sample Diluent 25 ml Blue
Sealing Tape 2 sheets
Cell Lysis Buffer (10X) 9803 15 ml Yellowish
Page

ELISA Colorimetric (Lyophilized)

A. Solutions and Reagents

NOTE: Prepare solutions with purified water.

  1. Microwell strips: Bring all to room temperature before use.
  2. Detection Antibody: Supplied lyophilized as a green colored cake or powder. Add 1.0 ml of Detection Antibody Diluent (green solution) to yield a concentrated stock solution. Incubate at room temperature for 5 min with occasional gentle mixing to fully reconstitute. To make the final working solution, add the full 1.0 ml volume of reconstituted Detection Antibody to 10.0 ml of Detection Antibody Diluent in a clean tube and gently mix. Unused working solution may be stored for 4 weeks at 4°C.
  3. HRP-Linked Antibody*: Supplied lyophilized as a red colored cake or powder. Add 1.0 ml of HRP Diluent (red solution) to yield a concentrated stock solution. Incubate at room temperature for 5 min with occasional gentle mixing to fully reconstitute. To make the final working solution, add the full 1.0 ml volume of reconstituted HRP-Linked Antibody to 10.0 ml of HRP Diluent in a clean tube and gently mix. Unused working solution may be stored for 4 weeks at 4°C.
  4. Detection Antibody Diluent: Green colored diluent for reconstitution and dilution of the detection antibody (11 ml provided).
  5. HRP Diluent: Red colored diluent for reconstitution and dilution of the HRP‑Linked Antibody (11 ml provided).
  6. Sample Diluent: Blue colored diluent provided for dilution of cell lysates.
  7. 1X Wash Buffer: Prepare by diluting 20X Wash Buffer (included in each PathScan® Sandwich ELISA Kit) in purified water.
  8. Cell Lysis Buffer: 10X Cell Lysis Buffer #9803: This buffer can be stored at 4°C for short-term use (1–2 weeks). Recommended: Add 1 mM phenylmethylsulfonyl fluoride (PMSF) immediately before use.
  9. TMB Substrate (#7004).
  10. STOP Solution (#7002).

*NOTE: Some PathScan® ELISA Kits may include HRP-Linked Streptavidin in place of HRP-Linked Antibody.

B. Preparing Cell Lysates

For adherent cells.

  1. Aspirate media when the culture reaches 80–90% confluence. Treat cells by adding fresh media containing regulator for desired time.
  2. Remove media and rinse cells once with ice-cold 1X PBS.
  3. Remove PBS and add 0.5 ml ice-cold 1X Cell Lysis Buffer plus 1 mM PMSF to each plate (10 cm diameter) and incubate the plate on ice for 5 min.
  4. Scrape cells off the plate and transfer to an appropriate tube. Keep on ice.
  5. Sonicate lysates on ice.
  6. Microcentrifuge for 10 min (x14,000 rpm) at 4°C and transfer the supernatant to a new tube. The supernatant is the cell lysate. Store at −80°C in single-use aliquots.

For suspension cells

  1. Remove media by low speed centrifugation (~1200 rpm) when the culture reaches 0.5–1.0 x 106 viable cells/ml. Treat cells by adding fresh media containing regulator for desired time.
  2. Collect cells by low speed centrifugation (~1200 rpm) and wash once with 5–10 ml ice-cold 1X PBS.
  3. Cells harvested from 50 ml of growth media can be lysed in 2.0 ml of 1X Cell Lysis Buffer plus 1 mM PMSF.
  4. Sonicate lysates on ice.
  5. Microcentrifuge for 10 min (x14,000 rpm) at 4°C and transfer the supernatant to a new tube. The supernatant is the cell lysate. Store at −80°C in single-use aliquots.

C. Test Procedure

  1. After the microwell strips have reached room temperature, break off the required number of microwells. Place the microwells in the strip holder. Unused microwells must be resealed and stored at 4°C immediately.
  2. Cell lysates can be undiluted or diluted with Sample Diluent (supplied in each PathScan® Sandwich ELISA Kit, blue color). Individual datasheets for each kit provide a sensitivity curve that serves as a reference for selection of an appropriate starting lysate concentration. The sensitivity curve shows typical kit assay results across a range of lysate concentration points.
  3. Add 100 µl of each undiluted or diluted cell lysate to the appropriate well. Seal with tape and press firmly onto top of microwells. Incubate the plate for 2 hr at 37°C. Alternatively, the plate can be incubated overnight at 4°C.
  4. Gently remove the tape and wash wells:
    1. Discard plate contents into a receptacle.
    2. Wash 4 times with 1X Wash Buffer, 200 µl each time for each well.
    3. For each wash, strike plates on fresh towels hard enough to remove the residual solution in each well, but do not allow wells to completely dry at any time.
    4. Clean the underside of all wells with a lint-free tissue.
  5. Add 100 µl of reconstituted Detection Antibody (green color) to each well (refer to Section A, Step 2). Seal with tape and incubate the plate at 37°C for 1 hr.
  6. Repeat wash procedure (Section C, Step 4).
  7. Add 100 µl of reconstituted HRP-Linked secondary antibody (red color) to each well (refer to Section A, Step 3). Seal with tape and incubate the plate for 30 min at 37°C.
  8. Repeat wash procedure (Section C, Step 4).
  9. Add 100 µl of TMB Substrate to each well. Seal with tape and incubate the plate for 10 min at 37°C or 30 min at 25°C.
  10. Add 100 µl of STOP Solution to each well. Shake gently for a few seconds.

NOTE: Initial color of positive reaction is blue, which changes to yellow upon addition of STOP Solution.

  1. Read results.
    1. Visual Determination: Read within 30 min after adding STOP Solution.
    2. Spectrophotometric Determination: Wipe underside of wells with a lint-free tissue. Read absorbance at 450 nm within 30 min after adding STOP Solution.

posted November 2013

protocol id: 204

Product Description

PathScan® Total CD44 Sandwich ELISA Kit is a solid phase sandwich enzyme-linked immunosorbent assay (ELISA) that detects endogenous levels of CD44 protein. A CD44 mouse mAb has been coated onto the microwells. After incubation with cell lysates, CD44 is captured by the coated antibody. Following extensive washing, a CD44 biotinylated Mouse Detection mAb is added to detect the captured CD44 protein. HRP-linked streptavidin is then used to recognize the bound detection antibody. HRP substrate, TMB, is added to develop color. The magnitude of absorbance for this developed color is proportional to the quantity of CD44 protein.

Antibodies in kit are custom formulations specific to kit.


Specificity / Sensitivity

PathScan® Total CD44 Sandwich ELISA Kit detects endogenous levels of total CD44 protein as shown in Figure 1. The kit sensitivity is shown in Figure 2. This kit detects proteins from the indicated species, as determined through in-house testing, but may also detect homologous proteins from other species.


Species Reactivity: Human

CD44 is a type I transmembrane glycoprotein that mediates cell-cell and cell-matrix interaction through its affinity for hyaluronic acid (HA) and possibly through other parts of the extracellular matrix (ECM). CD44 is highly polymorphic, possesses a number of alternative splice variants and undergoes extensive post-translational modifications (1,2). Increased surface levels of CD44 are characteristic of T cell activation, and expression of the protein is upregulated during the inflammatory response. Research studies have shown that interactions between CD44 and HER2 are linked to an increase in ovarian carcinoma cell growth (1-3). CD44 interacts with ezrin, radixin and moesin (ERM), linking the actin cytoskeleton to the plasma membrane and the ECM (4-6). CD44 is constitutively phosphorylated at Ser325 in resting cells. Activation of PKC results in phosphorylation of Ser291, dephosphorylation of Ser325, disassociation of ezrin from CD44, and directional motility (4).


1.  Goodison, S. et al. (1999) Mol. Pathol. 52, 189-196.

2.  Cichy, J. and Puré, E. (2003) J. Cell Biol. 161, 839-843.

3.  Bourguignon, L.Y. et al. (1997) J. Biol. Chem. 272, 27913-27918.

4.  Legg, J.W. et al. (2002) Nat. Cell Biol. 4, 399-407.

5.  Yonemura, S. et al. (1998) J. Cell Biol. 140, 885-895.

6.  Tsukita, S. et al. (1994) J. Cell Biol. 126, 391-401.


Entrez-Gene Id 960
Swiss-Prot Acc. P16070


For Research Use Only. Not For Use In Diagnostic Procedures.
Cell Signaling Technology® is a trademark of Cell Signaling Technology, Inc.
PathScan® is a trademark of Cell Signaling Technology, Inc.