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EL-C1600N100013-B
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Probe domestic switch needle KG300B head diameter 3.0 normally closed switch needle total length is 5
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SMD aluminum electrolytic capacitor
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0603 pink 0603 pink
All test wells are colorless <br>causes may be due to enzyme conjugate or substrate failure, substrate leakage (missing), positive control miss or addition, where enzyme conjugate failure and substrate misfeed are common . The reason for finding the reason is to directly mix the enzyme conjugate with the substrate to observe the presence or absence of color development; if the color development, it indicates that the positive control is missing or the substrate is wrongly added; if no color is developed, the new enzyme conjugate is used. The substrate was mixed to observe the presence or absence of color development; the absence of coloration suggested that the substrate failed, and the coloration suggested that the original enzyme conjugate failed. In the case of determining whether the substrate is wrong or invalid, if a stop solution is added. Can be rewashed and then developed.
The reason for the color development of all the detection holes is mostly that the plate is not clean (unbound enzyme conjugate in the residue) or the color development time is too long. Washing the plate is an important part of elisa testing. Should be strictly in accordance with the instructions, can properly extend the soaking time, increase the number of washings l ~ 2 times, otherwise it is easy to lead to false positives (competitive inhibition method is false negative) results.
The colorless pores of the quality control pores are generally caused by the decrease in the activity of the enzyme conjugate (excluding substrate misfeeds, failures, and leakage of controls). The quality control is generally a critical value and is an important basis for determining the success of the test. Although the positive control showed color, it could be found that the absorbance changed greatly. The batch test should be repeated to prevent the missed detection of weak positive results.
The color of the substrate is currently the original color of the domestic elisa kit is usually A, B liquid, respectively, a certain concentration of hydrogen peroxide and tetramethylbenzidine (TMB) or o-phenylenediamine (OPD) solution, they are Unstable, easy to produce color when used improperly; found color when used (or each drop of color after mixing), indicating that they are degraded or contaminated and must be discarded.
Analysis of common problems in ELISA experiment Description Causes Abnormal results after step Countermeasures white color, no color all wells microplate. The positive control did not develop color. Term reagent has passed, or mix different components of the kit components and the test reagent lot number, expiration, and all confirmed not belong to the corresponding components of a kit. Different kits or different batches of reagents cannot be mixed. Mis-add, leaking reagent substrate, developer A or B strictly follow the steps of the manual. After adding the reagent, you can observe whether the liquid level is consistent or not to reduce the leakage. Plates were washed and loading process, the enzyme-labeled by catalytic ability of the color developer contaminated enzyme inactivation lost acknowledgment filled container without enzyme inhibitor such as sodium azide, and was confirmed formulated lotion container is cleaned. Stop solution mistaken for diluting or washing liquid when the substrate buffer solution formulation should read the label indicating each substance in question to confirm distilled purified water wash formulated to meet the requirements and no pollution, compared with the distilled water is good. Significant color weakness, low sensitivity after the experiment, all colors including positive control wells, including quality control compared with light. If the kit expires, the product that exceeds the expiration date may generate a weak signal; the kit is not stored as specified, and is affected by high temperature; check the reagent composition and batch number before the experiment to confirm that the reagent has not expired. Do not store the kit at room temperature for a long time and store it according to the regulations. Unbalanced before reagent, samples were taken from room temperature to low temperature freezer set to the reagents and samples should be equilibrated to room temperature for about 20 minutes. The volume and time of adding the reagent are incorrect, the pipette is not accurately metered, the moisture in the nozzle is too much or not clean; the volume of the reagent used is determined to be correct, and the addition time is appropriate. Correct the pipette, and the pipette and the nozzle should be closely matched. The pipetting should not be too fast and the discharge should be complete. Plates were washed and loading process, inactivation of enzyme contaminated and lose the ability to catalyze a color developer confirmation filled container free enzyme inhibitors such as sodium azide, and was confirmed formulated lotion container is cleaned, It was confirmed that the purified water for the preparation of the washing liquid was satisfactory and was not contaminated. Incubation time and incubation temperature did not meet the requirements. When the reaction plate was placed in the incubator, pay attention to the temperature and adjust it in time. Incubation temperature should be controlled at 37-38 ° C, the incubation time is strictly in accordance with the instructions. It is not advisable to open the door during the heat preservation period to avoid affecting the heat preservation. The number of washings is too many, or the dilution factor of the concentrated washing liquid does not meet the requirements; the washing impact force is too large. Soaking time is too long; strictly dilute the concentrated washing liquid and wash the plate according to the instructions, reduce the washing impact force, and reserve the washing liquid time and washing times according to the instructions. The amount of the developer is insufficient or reversed, or added after mixing; the developer bottle is vertically downward, the holding force is uniform, and the dropping speed should not be too fast. First, the developer A is added, and then the coloring agent B is added. A, effect of the addition of the substrate B were mixed enough time; accurate timings. There is a problem with the quality of distilled water; the effect of reagents prepared with distilled water on enzyme immunoassay is determined. After the experiment, the normal control negative and positive, normal quality control, clinical specimens but feel weak color samples may be tested does not contain strong positive samples, it is normal if the result may be suspected, the sample can retest added sodium azide ELISA experiments as a preservative specimen disabled as a preservative sodium azide, Proclin choice, other preservative thimerosal normal control negative and positive, but quality control, with reference to individual chemical or weakly positive specimens could not be detected. Less than the required incubation time and incubation temperature can be detected strongly positive samples, but quality control, or weakly positive specimens influenced by temperature change is not detected in control materials or samples to avoid repeated freezing and thawing. Samples used within one week can be stored at 2-8 ° C, if long-term preservation, should be stored below -20 ° C. The control should be dispensed in small quantities and stored at -20 °C. Quality control materials or samples left at high temperature for too long, or repeated freezing and thawing test titer induced decrease could not be detected in a microplate reader reset parameters, in particular to check whether the filter matches. Instrument is not correctly set, filter does not match the parameter reset microplate reader, especially to check whether the filter matches
The storage of the kit should be carried out in accordance with the requirements of the instructions. The elisa test should be carried out in strict accordance with the elisa operating rules to avoid common experimental problems in elisa testing.