Camera in changing scenes automatically assign a boxcollider in the Inspecter.

I have a Gameobject with a boxcollider2D on it and Camera with the following code on it:

 using UnityEngine;
 using System.Collections;
 public class FollowCamera : MonoBehaviour {
 
 
         public Transform Player;
         private static bool CamExists;
 
         public Vector2 
         Margin,
         Smoothing;
 
         public BoxCollider2D Bounds;
 
         private Vector3
         _min,
         _max;
 
         public bool IsFollowing { get; set; }
 
         public void Start()
         {
             _min = Bounds.bounds.min;
             _max = Bounds.bounds.max;
             IsFollowing = true;
         if (!CamExists) {
         CamExists = true;
         DontDestroyOnLoad (transform.gameObject);
 
         } else {
         Destroy (gameObject);
         }
         }
 
         public void Update()
         {
             var x = transform.position.x;
             var y = transform.position.y;
 
             if (IsFollowing) 
             {
                 if (Mathf.Abs(x = Player.position.x) > Margin.x)
                     x = Mathf.Lerp (x, Player.position.x, Smoothing.x * Time.deltaTime);
 
                 if (Mathf.Abs(y = Player.position.y) > Margin.y)
                     y = Mathf.Lerp(y, Player.position.x, Smoothing.y * Time.deltaTime);
 
             }
 
             var cameraHalfWidth = GetComponent<Camera>().orthographicSize * ((float)Screen.width / Screen.height);?
 
             x = Mathf.Clamp(x, _min.x + cameraHalfWidth, _max.x - cameraHalfWidth);
             y = Mathf.Clamp(y, _min.y + GetComponent<Camera>().orthographicSize, _max.y - GetComponent<Camera>().orthographicSize);
 
             transform.position = new Vector3 (x, y, -10);
 
         }
     }

My BoxCollider2D tells the Camera when to stop. But the shape of it must change from scene to scene. How do I set the public BoxCollider2D to be the right shape in runtime? Thanks