The .qbt File

To create applications using MyQubit, several key assay parameters must first be defined externally using a PC and a simple word processor such as Notepad software,  For your convenience, a MyQubit file template can be downloaded here.   Each MyQubit file can store information for up to four unique assays.  The template provided on this page includes parameters for a single assay.  To add additional assays, simply copy and paste the appropriate fields below the entries for assay “Name 1”.  Additional assay name headers must be defined as “Name 2”, “Name 3”, and “Name 4”.  Although all fields may not be populated for every assay, all field headers must be included for each assay in the MyQubit file in order for the file to upload properly.  Table 1 describes the different fields that comprise a MyQubit file and provides guidelines for defining them.

MyQubit File Parameters & Definitions

Parameter Accepted Values Description
Parent Name(user defined, max 10 characters)Indicates the name visible on the initial Home Screen, i.e. the “family” of assays.  For example, “DNA” is a Parent Name for the existing instrument.
Name1 (and Name2, 3, 4)(user defined, max 10 characters)Indicates the individual assay name.  For example, “dsDNA” for the existing instrument.
Name Sub-text(user defined, max 20 characters)Indicates any smaller sub-text under the assay name (or to the right of the assay name from the graphical display).  For example, “High Sensitivity” for the existing instrument.
CalibrationYES or NOIndicates whether you are creating an assay that requires calibration or not.  “YES” indicates that the assay will require calibration.  All assays created using MyQubit that require calibration will utilize two standards, the first of which is always a sample blank (analyte concentration of “0”) and the second of which is a sample of a concentration to be determined by the user. “NO” indicates that the assay will not require calibration.  In this case, the output will be a raw fluorescence value or values. ACCEPTED VALUES
Units(user defined, text only, max 10 characters)Only required when Calibration is “YES.”  Maximum length 10 characters.
ExcitationBLUE, RED, BOTH, or NONEBOTH and NONE are only acceptable if Calibration is “NO.”  Otherwise, this constitutes an error and the .qbt file will not upload. BLUE = 470 nm, filter 430 – 495 nm. RED   = 635 nm, filter 600 – 645 nm. ACCEPTED VALUES
EmissionGREEN, FAR RED, or BOTHBOTH is only acceptable if Calibration is “NO.”  Otherwise, this constitutes an error and the .qbt file will not upload. GREEN = 510 – 580 nm. FAR RED = 665 – 725 nm. ACCEPTED VALUES
Std Signal Ratio Limit(user defined, numeric only)Only needed when Calibration is “YES.” This number specifies the amount, in raw fluorescence, that the signal for Standard #2 must exceed the signal for Standard #1 for your MyQubit assay.  This is meant to help troubleshoot large oversights in calibration.  If you are unsure of a reasonable threshold, or if this is not of concern to you, then enter a small value that you will be assured of attaining in most calibrations.
Low(user defined, numeric only)Only needed when Calibration is “YES.”  Indicates the lowest sample concentration that the instrument will display a result for.  Samples with concentrations below this value will be reported as “< Low” and will display the message “*Sample TOO LOW*”
High(user defined, numeric only)Only needed when Calibration is “YES.”  Indicates the highest sample concentration that the instrument will display a result for.  Samples with concentrations above this value will be reported as “> High” and will display the message “*Sample TOO HIGH*” 
N(user defined, numeric only)Only needed when Calibration is “YES.”  One of three algorithm constants that must be determined by the user.  Indicates the linearity of the curve, with a value of 1.00 corresponding to completely linear.
K(user defined, a scaling factor, numeric only)Only needed when Calibration is “YES.”  One of three algorithm constants that must be determined by the user.  Indicates the portion of the curve to focus on. 
S(user defined, numeric only)Only needed when Calibration is “YES.”  One of three algorithm constants that must be determined by the user.  Indicates the concentration value of Standard #2 used in assay calibration.
Green RFU Name(user defined, max 20 characters)Indicates the name given to the displayed RFU output for Green emission when Calibration is “NO.”  Only needed when Calibration is “NO” and Emission is “GREEN” or “BOTH.”
Far Red RFU Name(user defined, max 20 characters)Indicates the name given to the displayed RFU output for Far Red emission when Calibration is “NO.”  Only needed when Calibration is “NO” and Emission is “FAR RED” or “BOTH.”

 

Table 1.

Creating a .qbt File

When creating your own MyQubit file, use a simple word processor such as Notepad.  A more complex software package such as Microsoft® Word is unnecessary and can result in errors when uploading files to the instrument.  A .txt file should be created to define the fields described in Table 1.  After creating a new MyQubit .txt file, the file must be saved with the extension .qbt (the provided template is already saved with the .qbt file extension).  The Qubit® 2.0 Fluorometer will not recognize files with the .txt extension.  MyQubit files should first be created and saved externally to the Qubit® 2.0 Fluorometer on a PC and then transferred to the USB drive provided with the instrument (or other suitable USB drive).. The name of the file should not contain more than 20 characters from the standard ASCII library, with the exception that commas should not be used.  When uploading a new assay or assays to your instrument, make sure there is only one .qbt file on the USB drive.  Having multiple .qbt files present on the USB drive will result in an error when uploading the file to the Qubit® 2.0 Fluorometer.

Assays Without Calibration

New assays that do not require calibration can also be created with MyQubit.  For this sort of new application, raw fluorescence values are the output.  You may select which combination of excitation and emission channels you wish to use, as well as the name(s) of the output (maximum length of 20 characters).  This varies somewhat from Qubit® Raw mode, which automatically reads samples in both emission channels. See Table 1 for clarification on which parameters must be defined.