Application of CAPS (CAS 1135-40-6) in Protein Transmembrane Experiment

Introduction

CAPS, 3-(cyclohexylamine)-1-propanesulfonic acid, an organic chemical, white crystalline powder, CAS1135-40-6, is a biological buffer, commonly used in biochemical diagnostic kits, DNA/RNA extraction kits and PCR diagnostic kits. Buffer for enzyme chemistry and HPLC separation of basic drugs is widely used in the membrane transfer process of protei sequencing. CAPS buffer is composed of CAPS, deionized water, etc., and its pH is adjusted to 11.0 for purificationof fibronectin.

CAPS buffer

Key points of operation

1. SDS-PAGE electrophoresis: according to the conventional conditions (CAPS system: for > = 20kD protein; Tris Tricine system: for low molecular weight protein, also for high molecular weight protein);

2. Methanol concentration: the range of methanol concentration in CAPS electroimprinting buffer is 0-20% (methanol concentration is high, used for low molecular weight protein transfer; methanol concentration is low or even does not contain methanol, used for high molecular weight protein transfer);

3.PVDF membrane treatment: take out the PVDF membrane, soak it in methanol for several seconds, and then put it into the CAPS electroblotting buffer. (Note: the PVDF membrane shall be prevented from drying up after operation. If the membrane is dry, repeat the operation of this step);

4. Gel treatment: remove gel gel and soak in CAPS buffer for 5-10 minutes. (Note: this step can be omitted when transferring some strong basic proteins PI > 9.0);

5. Install the transfer slot: immerse the filter paper and sponge in the electro blotting buffer, then press the electrical imprinting sandwich in the order of sponge, filter paper, PVDF film, gel, filter paper and sponge, and put it into a small electric rotary slot.

6. Transfer conditions: transfer at 50V constant pressure (100-170 MA) at room temperature for 0.5-2h. (Note: drain the bubbles between the gel and PVDF film. For example, the protein above 70 KD should be transferred for longer time);

7. Pretreatment of PVDF membrane dyeing: take out PVDF membrane and rinse it with deionized water, soak it in methanol for several seconds, then dye it;

8. Membrane dyeing: Coomassie brilliant blue dyeing (dissolve 0.1% Coomassie brilliant blue R-250 in 40% methanol/1% acetic acid) for 30-50 seconds (not more than 1 minute), decolorizing with 50% methanol (change decolorizing solution frequently), washing with deionized water fully, and then drying;

CAPS buffer preparation

1. 10×CAPS(100mmol/L) buffer solution is prepared as follows: CAPS, 22.13g; add deionized water to 900ml; adjust the pH value to 11.0 with 2mol/L NaOH (about 20ml), then dilute to 1L, and store at 4℃.

2. CAPS electroimprinting buffer (1×CAPS containing 10% methanol) is prepared by the following methods: 200ml of 10 × CAPS; 200ml of methanol; 1600ml of deionized water.

Other applications

CAPS is also used to manufacture welding materials, air conditioning equipment and raw materials for manufacturing; it is also used to manufacture pyrotechnics; it is used as analytical reagent, heat exchange carrier, and also used in pharmaceutical industry; it is used for air conditioning, pyrotechnics, dry batteries; it is also used as flux and desiccant; it is used for curing agent of aqueous isocyanate in paint industry. Desheng company specializes in R&D and production of various biological buffers, including CAPS, Tris, Bicine, MOPS, etc., with high purity ≥ 99%, stable process, welcome enterprises and individuals to further consultation.