2.0 mL, Protein Low Binding Tube, "PROKEEP", Round Bottom "PK-20C-500" (500 tubes)

PROKEEP - Protein Low Binding Tube

PROKEEP is a high quality tube developed for the use of protein or peptide analysis (SDS-PAGE, HPLC, MS) as it mitigates the risk of the sample loss during experiment and preservation, and improves the signals detection.

Our special blending plastic materials avoid problem caused by elution from the tube

PROKEEP tubes reduce protein binding as a result of using our special blending of raw materials with low protein/peptide absorption and our technique of high precision finishing on the mold (no surface treatment on PROKEEP). With PROKEEP, elution from the tube can be avoided and better experiment result on MALDI MS analysis and Protein Chip analysis can be anticipated (See below).

PROKEEP's Protein Low Binding performance

Loss of protein and peptide when using plastic containers is caused by the following two factors.
a. Solution remained in the container after pipetting or centrifuge.
b. Adsorption of protein and peptide to the plastic containers.
PROKEEP has been developed by approaching both of two factors.
Watson's PROKEEP containers are incomparable in terms of achieving a low residue signal.
PROKEEP's residue signal is approximately 1 / 20 million, which is 1 / 850 residue amount of other conventional hydrophilic products in the following factor (1).
No occurrence of peptide signal loss during 2 weeks-storage in the following factor (2).

（1）Residue Protein Amount: Fig 1

Test Method:
FITC-BSA solution (1 µg/mL) was put in a microtube and left for 1 hour at room temperature. The fluorescence of the surface of the tube was measured and digitized after removal of the solution, and then the residual protein mass was analyzed. This method evaluates the residual amount of protein on the surface of the tube.
Results:
The residue amount on PROKEEP low protein binding tube is extremely low, which is 1 / 20million of the protein added. Tubes with hydrophilic surface treatment exhibited higher residue amount due to characteristic of the treatment.(Fig.1)

（2）Adsorption of protein and peptide to the tube: Fig 2

Test Method:
A solution（0.1％TFA, 10 µL) equivalent to 500 fmol/µL peptide mix contained in Bruker Daltonics's Peptide calibration standard（#206195) was put in a tube and kept at 4℃ for 2 weeks. Then, the peptide in the tube was collected and analyzed by mass spectrometer（Bruker Daltonics's Ultraflex tof/ tof）.
Results:
In the case of PROKEEPs low protein binding tube, all the peaks were detected after the 2 weeks. Conventional tube's showed a part of the peaks were undetectable and peptide loss by adsorption was observed (Fig 2B).

(3) Crystallization on MALDI Target Plate

Test Method:
In the crystallization process on a target plate, which is the indispensable process of MALDI type mass spectrometer analysis, a sample collected from another company's hydrophilic treated tube exhibited a disturbance in crystallization and it was difficult to conduct an accurate measurement, and elution of resin content was suspected(Fig. 3). PROKEEPs low protein binding tube showed equivalent performance to the tube recommended by Bruker Daltonics.

Material: Virgin Polypropylene
Centrifugal force: 7,000 x G (water 1.5 mL / 15 minutes)
With scale (500 / 1000 / 1500 / 2000 µL)
Flat top (with marking space)

Locking mechanism
Safety lock system is equipped. Hard type and soft type are available.

Friendly hinge for finger
Pounded and embossed cap-edge reduces irritation to the finger, and makes it easier to close the cap.

Scale
The volume is easily recognized with the scale for each 0.5 mL described on the tube.

Contamination prevention
Lock part prevents the thumb from touching the inner cap when opening and closing.

Unique shape of cap
Easy opening cap with less force. Flat cap allows marking on the top.

Writing space
Writing space is available on the surface of tube (opposite side from the scale side).

Nuclease-free guaranteed
This mark shows RNase/DNase/Human-DNA free. Products with this mark are manufactured in the clean room under our high quality control, and inspected to meet our strict quality standards. A document with this mark can be issued for each lot upon your request.